From d210957cd8f48768e2993f2cc1cf9ba4f6a6afac Mon Sep 17 00:00:00 2001
From: Demi Obenour <demiobenour@gmail.com>
Date: Fri, 14 Jul 2017 18:51:10 -0400
Subject: [PATCH 01/17] Add mostly-complete support for Reddit-style autolinks

Links of form u/a are still broken (leading '/' in href is missing).
---
 md2html/md2html.c     |  7 +++++++
 md2html/render_html.c |  2 +-
 md4c/md4c.c           | 24 ++++++++++++++++++++++++
 md4c/md4c.h           |  2 ++
 4 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/md2html/md2html.c b/md2html/md2html.c
index f9a5548a..02f84c3f 100644
--- a/md2html/md2html.c
+++ b/md2html/md2html.c
@@ -195,6 +195,7 @@ static const option cmdline_options[] = {
     { "version",                    'v', 'v', OPTION_ARG_NONE },
     { "commonmark",                  0,  'c', OPTION_ARG_NONE },
     { "github",                      0,  'g', OPTION_ARG_NONE },
+    { "reddit",                      0,  'R', OPTION_ARG_NONE },
     { "fverbatim-entities",          0,  'E', OPTION_ARG_NONE },
     { "fpermissive-atx-headers",     0,  'A', OPTION_ARG_NONE },
     { "fpermissive-url-autolinks",   0,  'U', OPTION_ARG_NONE },
@@ -208,6 +209,7 @@ static const option cmdline_options[] = {
     { "fcollapse-whitespace",        0,  'W', OPTION_ARG_NONE },
     { "ftables",                     0,  'T', OPTION_ARG_NONE },
     { "fstrikethrough",              0,  'S', OPTION_ARG_NONE },
+    { "freddit-autolinks",           0,  'r', OPTION_ARG_NONE },
     { 0 }
 };
 
@@ -229,6 +231,7 @@ usage(void)
         "(note these are equivalent to some combinations of flags below)\n"
         "      --commonmark     CommonMark (this is default)\n"
         "      --github         Github Flavored Markdown\n"
+        "      --reddit         Reddit's dialect of Markdown\n"
         "\n"
         "Markdown extension options:\n"
         "      --fcollapse-whitespace\n"
@@ -253,6 +256,8 @@ usage(void)
         "      --fno-html-spans\n"
         "                       Disable raw HTML spans\n"
         "      --fno-html       Same as --fno-html-blocks --fno-html-spans\n"
+        "      --freddit-autolinks\n"
+        "                       Enable Reddit autolinks of the form /u/x, /r/x, u/x, r/x\n"
         "      --ftables        Enable tables\n"
         "      --fstrikethrough Enable strikethrough spans\n"
     );
@@ -288,6 +293,7 @@ cmdline_callback(int opt, char const* value, void* data)
 
         case 'c':   parser_flags = MD_DIALECT_COMMONMARK; break;
         case 'g':   parser_flags = MD_DIALECT_GITHUB; break;
+        case 'R':   parser_flags = MD_DIALECT_REDDITPOST; break;
 
         case 'E':   renderer_flags |= MD_RENDER_FLAG_VERBATIM_ENTITIES; break;
         case 'A':   parser_flags |= MD_FLAG_PERMISSIVEATXHEADERS; break;
@@ -302,6 +308,7 @@ cmdline_callback(int opt, char const* value, void* data)
         case 'V':   parser_flags |= MD_FLAG_PERMISSIVEAUTOLINKS; break;
         case 'T':   parser_flags |= MD_FLAG_TABLES; break;
         case 'S':   parser_flags |= MD_FLAG_STRIKETHROUGH; break;
+        case 'r':   parser_flags |= MD_FLAG_REDDITAUTOLINKS;
 
         default:
             fprintf(stderr, "Illegal option: %s\n", value);
diff --git a/md2html/render_html.c b/md2html/render_html.c
index 6f91d0db..fa0cf9b9 100644
--- a/md2html/render_html.c
+++ b/md2html/render_html.c
@@ -307,7 +307,7 @@ render_open_a_span(MD_RENDER_HTML* r, const MD_SPAN_A_DETAIL* det)
         render_attribute(r, &det->title, render_html_escaped);
     }
 
-    RENDER_LITERAL(r, "\">");
+    RENDER_LITERAL(r, "\" rel=\"nofollow noopener noreferrer\">");
 }
 
 static void
diff --git a/md4c/md4c.c b/md4c/md4c.c
index 0b10c729..f5b2a667 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -2668,6 +2668,8 @@ md_build_mark_char_map(MD_CTX* ctx)
     ctx->mark_char_map['!'] = 1;
     ctx->mark_char_map[']'] = 1;
     ctx->mark_char_map['\0'] = 1;
+    if(ctx->r.flags & MD_FLAG_REDDITAUTOLINKS)
+        ctx->mark_char_map['/'] = 1;
 
     if(ctx->r.flags & MD_FLAG_STRIKETHROUGH)
         ctx->mark_char_map['~'] = 1;
@@ -2884,7 +2886,29 @@ md_collect_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int table_mode)
                     /* Push a dummy as a reserve for a closer. */
                     PUSH_MARK('D', off, off, 0);
                 }
+                off++;
+                continue;
+            }
 
+            /* A potential permissive Reddit autolink */
+            if(ch == _T('/')) {
+                if(line->beg + 1 <= off && (CH(off - 1) == 'u' || CH(off - 1) == 'r') &&
+                      (line->beg + 1 == off ||
+                         (CH(off - 2) != '/' && (ISUNICODEPUNCTBEFORE(off - 1) || ISUNICODEWHITESPACE(off - 2)))) &&
+                      line->end > off + 1 && ISALNUM(off + 1)) {
+                    /* u/something or r/something */
+                    PUSH_MARK(':', off - 1, off - 1, MD_MARK_POTENTIAL_OPENER);
+                    /* Push a dummy as a reserve for a closer. */
+                    PUSH_MARK('D', off, off, 0);
+                } else if (line->end > off + 3) {
+                    const char *buf = STR(off + 1);
+                    if (buf[1] == '/' && (buf[0] == 'u' || buf[0] == 'r') &&
+                        ISALNUM(off + 3)) {
+                        PUSH_MARK(':', off, off+1, MD_MARK_POTENTIAL_OPENER);
+                        /* Push a dummy as a reserve for a closer. */
+                        PUSH_MARK('D', off, off, 0);
+                    }
+                }
                 off++;
                 continue;
             }
diff --git a/md4c/md4c.h b/md4c/md4c.h
index 46acbeea..3908faeb 100644
--- a/md4c/md4c.h
+++ b/md4c/md4c.h
@@ -271,6 +271,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
 
 #define MD_FLAG_PERMISSIVEAUTOLINKS         (MD_FLAG_PERMISSIVEEMAILAUTOLINKS | MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEWWWAUTOLINKS)
 #define MD_FLAG_NOHTML                      (MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS)
+#define MD_FLAG_REDDITAUTOLINKS             0x8000  /* Enable Reddit autolinks */
 
 /* Convenient sets of flags corresponding to well-known Markdown dialects.
  * Note we may only support subset of features of the referred dialect.
@@ -279,6 +280,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
  */
 #define MD_DIALECT_COMMONMARK               0
 #define MD_DIALECT_GITHUB                   (MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_TABLES | MD_FLAG_STRIKETHROUGH)
+#define MD_DIALECT_REDDITPOST               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITAUTOLINKS)
 
 /* Renderer structure.
  */

From 4a8f087f0c6238fd05de0d845c0608af324709e9 Mon Sep 17 00:00:00 2001
From: Demi Obenour <demiobenour@gmail.com>
Date: Fri, 14 Jul 2017 19:12:23 -0400
Subject: [PATCH 02/17] Finish Reddit autolinks

---
 md4c/md4c.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/md4c/md4c.c b/md4c/md4c.c
index f5b2a667..8387117d 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -3601,6 +3601,9 @@ md_analyze_permissive_url_autolink(MD_CTX* ctx, int mark_index)
     OFF off = opener->end;
     int seen_dot = FALSE;
     int seen_underscore_or_hyphen[2] = { FALSE, FALSE };
+    if (opener->end == opener->beg) {
+        opener->ch = '/';
+    }
 
     /* Check for domain. */
     while(off < ctx->size) {
@@ -3748,6 +3751,7 @@ md_analyze_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
             case '_':   md_analyze_underscore(ctx, i); break;
             case '~':   md_analyze_tilde(ctx, i); break;
             case '.':   /* Pass through. */
+            case '/':   /* Pass through */
             case ':':   md_analyze_permissive_url_autolink(ctx, i); break;
             case '@':   md_analyze_permissive_email_autolink(ctx, i); break;
         }
@@ -3961,6 +3965,7 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                 case '@':       /* Permissive e-mail autolink. */
                 case ':':       /* Permissive URL autolink. */
                 case '.':       /* Permissive WWW autolink. */
+                case '/':       /* Permissive Reddit autolinks */
                 {
                     const MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
                     const MD_MARK* closer = &ctx->marks[opener->next];
@@ -3977,6 +3982,14 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                         dest = ctx->buffer;
                     }
 
+                    if(opener->ch == '/') {
+                        dest_size += 1;
+                        MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
+                        memcpy(ctx->buffer, _T("/"), 1 * sizeof(CHAR));
+                        memcpy(ctx->buffer + 1, dest, (dest_size-1) * sizeof(CHAR));
+                        dest = ctx->buffer;
+                    }
+
                     MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
                                 MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
                     break;

From 19e6c59a28dc5c9a97653d4ab9e90d63245714cf Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Sun, 7 Jan 2018 19:12:34 -0700
Subject: [PATCH 03/17] Fully working Reddit slash links

---
 md4c/md4c.c | 173 ++++++++++++++++++++++++++++++++++++++--------------
 md4c/md4c.h |  22 +++++--
 2 files changed, 144 insertions(+), 51 deletions(-)

diff --git a/md4c/md4c.c b/md4c/md4c.c
index d663f593..1778e7b5 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -2696,9 +2696,8 @@ md_build_mark_char_map(MD_CTX* ctx)
     ctx->mark_char_map['!'] = 1;
     ctx->mark_char_map[']'] = 1;
     ctx->mark_char_map['\0'] = 1;
-    if(ctx->r.flags & MD_FLAG_REDDITAUTOLINKS)
-        ctx->mark_char_map['/'] = 1;
-
+	if (ctx->r.flags & MD_FLAG_REDDITSLASHDETECTION)
+		ctx->mark_char_map['/'] = 1;
     if(ctx->r.flags & MD_FLAG_STRIKETHROUGH)
         ctx->mark_char_map['~'] = 1;
 
@@ -2923,24 +2922,39 @@ md_collect_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int table_mode)
                 if(line->beg + 1 <= off && (CH(off - 1) == 'u' || CH(off - 1) == 'r') &&
                       (line->beg + 1 == off ||
                          (CH(off - 2) != '/' && (ISUNICODEPUNCTBEFORE(off - 1) || ISUNICODEWHITESPACE(off - 2)))) &&
-                      line->end > off + 1 && ISALNUM(off + 1)) {
+                      line->end > off + 1 && ISALNUM(off + 1)) 
+				{
+					OFF index = off + 2;
+					while (index <= line->end)
+					{
+						if (!(ISALNUM(index) || (CH(index) == '_')))
+							break;
+						index++;
+					}
                     /* u/something or r/something */
-                    PUSH_MARK(':', off - 1, off - 1, MD_MARK_POTENTIAL_OPENER);
-                    /* Push a dummy as a reserve for a closer. */
-                    PUSH_MARK('D', off, off, 0);
-                } else if (line->end > off + 3) {
-                    const char *buf = STR(off + 1);
-                    if (buf[1] == '/' && (buf[0] == 'u' || buf[0] == 'r') &&
-                        ISALNUM(off + 3)) {
-                        PUSH_MARK(':', off, off+1, MD_MARK_POTENTIAL_OPENER);
-                        /* Push a dummy as a reserve for a closer. */
-                        PUSH_MARK('D', off, off, 0);
-                    }
+                    PUSH_MARK('/', off - 1, index, MD_MARK_RESOLVED);
+					off = index;
+                } 
+				else if (line->end > off + 3 && ((CH(off + 2) == '/') && (CH(off + 1) == 'u' || CH(off + 1) == 'r') &&
+					ISALNUM(off + 3)))
+				{
+					OFF index = off + 4;
+					while (index <= line->end)
+					{
+						if (!(ISALNUM(index) || (CH(index) == '_')))
+							break;
+							index++;
+					}
+                    PUSH_MARK('/', off, index, MD_MARK_RESOLVED);
+					off = index;
                 }
-                off++;
+				else
+				{
+					off++;
+				}
                 continue;
             }
-
+			
             /* A potential permissive URL autolink. */
             if(ch == _T(':')) {
                 static struct {
@@ -3738,7 +3752,6 @@ md_analyze_permissive_email_autolink(MD_CTX* ctx, int mark_index)
     closer->end = end;
     md_resolve_range(ctx, NULL, mark_index, closer_index);
 }
-
 static inline void
 md_analyze_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
                  int mark_beg, int mark_end, const CHAR* mark_chars)
@@ -3993,36 +4006,106 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                 case '@':       /* Permissive e-mail autolink. */
                 case ':':       /* Permissive URL autolink. */
                 case '.':       /* Permissive WWW autolink. */
-                case '/':       /* Permissive Reddit autolinks */
-                {
-                    const MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
-                    const MD_MARK* closer = &ctx->marks[opener->next];
-                    const CHAR* dest = STR(opener->end);
-                    SZ dest_size = closer->beg - opener->end;
-
-                    if(opener->ch == '@' || opener->ch == '.') {
-                        dest_size += 7;
-                        MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
-                        memcpy(ctx->buffer,
-                                (opener->ch == '@' ? _T("mailto:") : _T("http://")),
-                                7 * sizeof(CHAR));
-                        memcpy(ctx->buffer + 7, dest, (dest_size-7) * sizeof(CHAR));
-                        dest = ctx->buffer;
-                    }
+				{
 
-                    if(opener->ch == '/') {
-                        dest_size += 1;
-                        MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
-                        memcpy(ctx->buffer, _T("/"), 1 * sizeof(CHAR));
-                        memcpy(ctx->buffer + 1, dest, (dest_size-1) * sizeof(CHAR));
-                        dest = ctx->buffer;
-                    }
+					const MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
 
-                    MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
-                                MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
-                    break;
-                }
+					const MD_MARK* closer = &ctx->marks[opener->next];
+
+					const CHAR* dest = STR(opener->end);
+
+					SZ dest_size = closer->beg - opener->end;
 
+
+
+					if (opener->ch == '@' || opener->ch == '.') {
+
+						dest_size += 7;
+
+						MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
+
+						memcpy(ctx->buffer,
+
+							(opener->ch == '@' ? _T("mailto:") : _T("http://")),
+
+							7 * sizeof(CHAR));
+
+						memcpy(ctx->buffer + 7, dest, (dest_size - 7) * sizeof(CHAR));
+
+						dest = ctx->buffer;
+
+					}
+
+
+
+					MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
+
+						MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
+
+					break;
+
+				}
+                case '/':       /* Permissive Reddit autolinks */
+				{
+					MD_REDDIT_SLASH_DETAIL det;
+					if (CH(mark->beg) == '/')
+					{
+						det.name = ctx->text + mark->beg + 3;
+						det.size = mark->end - mark->beg - 3;
+						if (CH(mark->beg + 1) == 'r')
+						{
+							det.type = MD_REDDIT_SUBREDDIT;
+						}
+						else
+						{
+							det.type = MD_REDDIT_USER;
+						}
+					}
+					else // u/something or r/something instead of /r/something
+					{
+						det.name = ctx->text + mark->beg + 2;
+						det.size = mark->end - mark->beg - 2;
+						if (CH(mark->beg) == 'r')
+						{
+							det.type = MD_REDDIT_SUBREDDIT;
+						}
+						else
+						{
+							det.type = MD_REDDIT_USER;
+						}
+					}
+					if (ctx->r.flags & MD_FLAG_REDDIT_SLASHES_AS_LINKS)
+					{
+						MD_SPAN_A_DETAIL linkDet;
+						linkDet.href.size = (24 + (det.size));
+						linkDet.href.substr_offsets = NULL;
+						linkDet.href.substr_types = NULL;
+						MD_CHAR* link = (MD_CHAR*)malloc(sizeof(MD_CHAR) * linkDet.href.size);
+						linkDet.href.text = link;
+						linkDet.title.size = 0;
+						linkDet.title.substr_offsets = NULL;
+						linkDet.title.substr_types = NULL;
+						linkDet.title.text = NULL;
+						memcpy(link, _T("https://www.reddit.com/"), sizeof(MD_CHAR) * 23);
+						if (det.type == MD_REDDIT_SUBREDDIT)
+							link[23] = _T('r');
+						else
+							link[23] = _T('u');
+						link[24] = _T('/');
+						memcpy(link + 25, det.name, sizeof(MD_CHAR) * det.size);
+						MD_ENTER_SPAN(MD_SPAN_A, &linkDet);
+						MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
+						MD_LEAVE_SPAN(MD_SPAN_A, &linkDet);
+						free(link);
+					}
+					else 
+					{
+						MD_ENTER_SPAN(MD_REDDIT_SLASH_LINK, &det);
+						MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
+						MD_LEAVE_SPAN(MD_REDDIT_SLASH_LINK, &det);
+					}
+					
+				}break;
                 case '&':       /* Entity. */
                     MD_TEXT(MD_TEXT_ENTITY, STR(mark->beg), mark->end - mark->beg);
                     break;
diff --git a/md4c/md4c.h b/md4c/md4c.h
index d52bf9b5..fdbda7a0 100644
--- a/md4c/md4c.h
+++ b/md4c/md4c.h
@@ -131,7 +131,8 @@ typedef enum MD_SPANTYPE {
     /* <del>...</del>
      * Note: Recognized only when MD_FLAG_STRIKETHROUGH is enabled.
      */
-    MD_SPAN_DEL
+    MD_SPAN_DEL,
+	MD_REDDIT_SLASH_LINK
 } MD_SPANTYPE;
 
 /* Text is the actual textual contents of span. */
@@ -172,8 +173,10 @@ typedef enum MD_TEXTTYPE {
      * The text contains verbatim '\n' for the new lines. */
     MD_TEXT_HTML
 } MD_TEXTTYPE;
-
-
+typedef enum MD_REDDIT_SLASH_TYPE
+{
+	MD_REDDIT_USER, MD_REDDIT_SUBREDDIT
+} MD_REDDIT_SLASH_TYPE;
 /* Alignment enumeration. */
 typedef enum MD_ALIGN {
     MD_ALIGN_DEFAULT = 0,   /* When unspecified. */
@@ -245,7 +248,13 @@ typedef struct MD_SPAN_A_DETAIL {
     MD_ATTRIBUTE href;
     MD_ATTRIBUTE title;
 } MD_SPAN_A_DETAIL;
-
+typedef struct MD_REDDIT_SLASH_DETAIL
+{
+	MD_REDDIT_SLASH_TYPE type; //whether it's a user or subreddit
+	/*whether the name of the user or subreddit starts two or three characters away from the beginning. To get a pointer to the name text + offset*/
+	unsigned char size; //length of the whole thing, including the /r/ part.
+	MD_CHAR * name;
+}MD_REDDIT_SLASH_DETAIL;
 /* Detailed info for MD_SPAN_IMG. */
 typedef struct MD_SPAN_IMG_DETAIL {
     MD_ATTRIBUTE src;
@@ -271,7 +280,8 @@ typedef struct MD_SPAN_IMG_DETAIL {
 
 #define MD_FLAG_PERMISSIVEAUTOLINKS         (MD_FLAG_PERMISSIVEEMAILAUTOLINKS | MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEWWWAUTOLINKS)
 #define MD_FLAG_NOHTML                      (MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS)
-#define MD_FLAG_REDDITAUTOLINKS             0x8000  /* Enable Reddit autolinks */
+#define MD_FLAG_REDDITSLASHDETECTION             0x8000  /* Enable Reddit autolinks */
+#define MD_FLAG_REDDIT_SLASHES_AS_LINKS        0x4000 //Instead of making Reddit links into special spans, make them into web links
 
 /* Convenient sets of flags corresponding to well-known Markdown dialects.
  * Note we may only support subset of features of the referred dialect.
@@ -280,7 +290,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
  */
 #define MD_DIALECT_COMMONMARK               0
 #define MD_DIALECT_GITHUB                   (MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_TABLES | MD_FLAG_STRIKETHROUGH)
-#define MD_DIALECT_REDDITPOST               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITAUTOLINKS)
+#define MD_DIALECT_REDDITPOST               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITSLASHDETECTION | MD_FLAG_STRIKETHROUGH)
 
 /* Renderer structure.
  */

From c686873107c7faca6835008c770c25176f42ccd8 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <xiaocowow@gmail.com>
Date: Sun, 7 Jan 2018 19:37:17 -0700
Subject: [PATCH 04/17] Update md2html.c

---
 md2html/md2html.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/md2html/md2html.c b/md2html/md2html.c
index 02f84c3f..a3fd660c 100644
--- a/md2html/md2html.c
+++ b/md2html/md2html.c
@@ -308,7 +308,7 @@ cmdline_callback(int opt, char const* value, void* data)
         case 'V':   parser_flags |= MD_FLAG_PERMISSIVEAUTOLINKS; break;
         case 'T':   parser_flags |= MD_FLAG_TABLES; break;
         case 'S':   parser_flags |= MD_FLAG_STRIKETHROUGH; break;
-        case 'r':   parser_flags |= MD_FLAG_REDDITAUTOLINKS;
+        case 'r':   parser_flags |= MD_FLAG_REDDITSLASHDETECTION;
 
         default:
             fprintf(stderr, "Illegal option: %s\n", value);

From 0129aa521488b19cb321ec6dae2d4727d1d2835c Mon Sep 17 00:00:00 2001
From: Jimmy <jimmyjxiao@outlook.com>
Date: Sun, 7 Jan 2018 20:02:59 -0700
Subject: [PATCH 05/17] undo this because it breaks tests

---
 md2html/render_html.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/md2html/render_html.c b/md2html/render_html.c
index a079e6fd..8f0b22c0 100644
--- a/md2html/render_html.c
+++ b/md2html/render_html.c
@@ -307,7 +307,7 @@ render_open_a_span(MD_RENDER_HTML* r, const MD_SPAN_A_DETAIL* det)
         render_attribute(r, &det->title, render_html_escaped);
     }
 
-    RENDER_LITERAL(r, "\" rel=\"nofollow noopener noreferrer\">");
+    RENDER_LITERAL(r, "\">");
 }
 
 static void

From 0d5d4954754300028eea10c08e948e8252092178 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <xiaocowow@gmail.com>
Date: Sun, 7 Jan 2018 20:25:05 -0700
Subject: [PATCH 06/17] Update README.md

---
 README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/README.md b/README.md
index 6a77a338..65c443c5 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,8 @@ some extensions or allowing some deviations from the specification.
 
  * With the flag `MD_FLAG_NOINDENTEDCODEBLOCKS`, indented code blocks are
    disabled.
+   
+ * With the flag `MD_FLAG_REDDITSLASHDETECTION`, Reddit subreddit and user links such as r/test or /u/me are detected
 
 
 ## Input/Output Encoding

From fda1114303ecb5e0f4379343443514d2331d114e Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Sun, 7 Jan 2018 20:43:16 -0700
Subject: [PATCH 07/17] fix some comments:

---
 md4c/md4c.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/md4c/md4c.h b/md4c/md4c.h
index fdbda7a0..3ac15960 100644
--- a/md4c/md4c.h
+++ b/md4c/md4c.h
@@ -251,8 +251,7 @@ typedef struct MD_SPAN_A_DETAIL {
 typedef struct MD_REDDIT_SLASH_DETAIL
 {
 	MD_REDDIT_SLASH_TYPE type; //whether it's a user or subreddit
-	/*whether the name of the user or subreddit starts two or three characters away from the beginning. To get a pointer to the name text + offset*/
-	unsigned char size; //length of the whole thing, including the /r/ part.
+	unsigned char size; 
 	MD_CHAR * name;
 }MD_REDDIT_SLASH_DETAIL;
 /* Detailed info for MD_SPAN_IMG. */

From 93e9afdc318616c795db63b45a3069b352c8daf1 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 16:33:17 -0700
Subject: [PATCH 08/17] change Reddit flag name

---
 md4c/md4c.c | 2 +-
 md4c/md4c.h | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/md4c/md4c.c b/md4c/md4c.c
index 1778e7b5..d1b41d35 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -2696,7 +2696,7 @@ md_build_mark_char_map(MD_CTX* ctx)
     ctx->mark_char_map['!'] = 1;
     ctx->mark_char_map[']'] = 1;
     ctx->mark_char_map['\0'] = 1;
-	if (ctx->r.flags & MD_FLAG_REDDITSLASHDETECTION)
+	if (ctx->r.flags & MD_FLAG_REDDITAUTOLINKS)
 		ctx->mark_char_map['/'] = 1;
     if(ctx->r.flags & MD_FLAG_STRIKETHROUGH)
         ctx->mark_char_map['~'] = 1;
diff --git a/md4c/md4c.h b/md4c/md4c.h
index 3ac15960..e16bcf27 100644
--- a/md4c/md4c.h
+++ b/md4c/md4c.h
@@ -279,7 +279,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
 
 #define MD_FLAG_PERMISSIVEAUTOLINKS         (MD_FLAG_PERMISSIVEEMAILAUTOLINKS | MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEWWWAUTOLINKS)
 #define MD_FLAG_NOHTML                      (MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS)
-#define MD_FLAG_REDDITSLASHDETECTION             0x8000  /* Enable Reddit autolinks */
+#define MD_FLAG_REDDITAUTOLINKS             0x8000  /* Enable Reddit autolinks */
 #define MD_FLAG_REDDIT_SLASHES_AS_LINKS        0x4000 //Instead of making Reddit links into special spans, make them into web links
 
 /* Convenient sets of flags corresponding to well-known Markdown dialects.
@@ -289,7 +289,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
  */
 #define MD_DIALECT_COMMONMARK               0
 #define MD_DIALECT_GITHUB                   (MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_TABLES | MD_FLAG_STRIKETHROUGH)
-#define MD_DIALECT_REDDITPOST               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITSLASHDETECTION | MD_FLAG_STRIKETHROUGH)
+#define MD_DIALECT_REDDITPOST               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITAUTOLINKS | MD_FLAG_STRIKETHROUGH)
 
 /* Renderer structure.
  */

From 6bd03e7fe5fbc2933d3599467344bb4cedb7d638 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 16:34:34 -0700
Subject: [PATCH 09/17] Remove Reddit autolinks as web links option from md4c

---
 md4c/md4c.c | 36 ++++--------------------------------
 1 file changed, 4 insertions(+), 32 deletions(-)

diff --git a/md4c/md4c.c b/md4c/md4c.c
index d1b41d35..cfa34815 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -4045,7 +4045,7 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
 					break;
 
 				}
-                case '/':       /* Permissive Reddit autolinks */
+				case '/':       /* Permissive Reddit autolinks */
 				{
 					MD_REDDIT_SLASH_DETAIL det;
 					if (CH(mark->beg) == '/')
@@ -4074,37 +4074,9 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
 							det.type = MD_REDDIT_USER;
 						}
 					}
-					if (ctx->r.flags & MD_FLAG_REDDIT_SLASHES_AS_LINKS)
-					{
-						MD_SPAN_A_DETAIL linkDet;
-						linkDet.href.size = (24 + (det.size));
-						linkDet.href.substr_offsets = NULL;
-						linkDet.href.substr_types = NULL;
-						MD_CHAR* link = (MD_CHAR*)malloc(sizeof(MD_CHAR) * linkDet.href.size);
-						linkDet.href.text = link;
-						linkDet.title.size = 0;
-						linkDet.title.substr_offsets = NULL;
-						linkDet.title.substr_types = NULL;
-						linkDet.title.text = NULL;
-						memcpy(link, _T("https://www.reddit.com/"), sizeof(MD_CHAR) * 23);
-						if (det.type == MD_REDDIT_SUBREDDIT)
-							link[23] = _T('r');
-						else
-							link[23] = _T('u');
-						link[24] = _T('/');
-						memcpy(link + 25, det.name, sizeof(MD_CHAR) * det.size);
-						MD_ENTER_SPAN(MD_SPAN_A, &linkDet);
-						MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
-						MD_LEAVE_SPAN(MD_SPAN_A, &linkDet);
-						free(link);
-					}
-					else 
-					{
-						MD_ENTER_SPAN(MD_REDDIT_SLASH_LINK, &det);
-						MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
-						MD_LEAVE_SPAN(MD_REDDIT_SLASH_LINK, &det);
-					}
-					
+					MD_ENTER_SPAN(MD_REDDIT_SLASH_LINK, &det);
+					MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
+					MD_LEAVE_SPAN(MD_REDDIT_SLASH_LINK, &det);
 				}break;
                 case '&':       /* Entity. */
                     MD_TEXT(MD_TEXT_ENTITY, STR(mark->beg), mark->end - mark->beg);

From 44860406d3fc903d1eec93606b1844eae287c5bf Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 16:36:48 -0700
Subject: [PATCH 10/17] untabify

---
 md4c/md4c.c | 156 ++++++++++++++++++++++++++--------------------------
 md4c/md4c.h |  12 ++--
 2 files changed, 84 insertions(+), 84 deletions(-)

diff --git a/md4c/md4c.c b/md4c/md4c.c
index cfa34815..4f667889 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -2696,8 +2696,8 @@ md_build_mark_char_map(MD_CTX* ctx)
     ctx->mark_char_map['!'] = 1;
     ctx->mark_char_map[']'] = 1;
     ctx->mark_char_map['\0'] = 1;
-	if (ctx->r.flags & MD_FLAG_REDDITAUTOLINKS)
-		ctx->mark_char_map['/'] = 1;
+    if (ctx->r.flags & MD_FLAG_REDDITAUTOLINKS)
+        ctx->mark_char_map['/'] = 1;
     if(ctx->r.flags & MD_FLAG_STRIKETHROUGH)
         ctx->mark_char_map['~'] = 1;
 
@@ -2923,38 +2923,38 @@ md_collect_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int table_mode)
                       (line->beg + 1 == off ||
                          (CH(off - 2) != '/' && (ISUNICODEPUNCTBEFORE(off - 1) || ISUNICODEWHITESPACE(off - 2)))) &&
                       line->end > off + 1 && ISALNUM(off + 1)) 
-				{
-					OFF index = off + 2;
-					while (index <= line->end)
-					{
-						if (!(ISALNUM(index) || (CH(index) == '_')))
-							break;
-						index++;
-					}
+                {
+                    OFF index = off + 2;
+                    while (index <= line->end)
+                    {
+                        if (!(ISALNUM(index) || (CH(index) == '_')))
+                            break;
+                        index++;
+                    }
                     /* u/something or r/something */
                     PUSH_MARK('/', off - 1, index, MD_MARK_RESOLVED);
-					off = index;
+                    off = index;
                 } 
-				else if (line->end > off + 3 && ((CH(off + 2) == '/') && (CH(off + 1) == 'u' || CH(off + 1) == 'r') &&
-					ISALNUM(off + 3)))
-				{
-					OFF index = off + 4;
-					while (index <= line->end)
-					{
-						if (!(ISALNUM(index) || (CH(index) == '_')))
-							break;
-							index++;
-					}
+                else if (line->end > off + 3 && ((CH(off + 2) == '/') && (CH(off + 1) == 'u' || CH(off + 1) == 'r') &&
+                    ISALNUM(off + 3)))
+                {
+                    OFF index = off + 4;
+                    while (index <= line->end)
+                    {
+                        if (!(ISALNUM(index) || (CH(index) == '_')))
+                            break;
+                            index++;
+                    }
                     PUSH_MARK('/', off, index, MD_MARK_RESOLVED);
-					off = index;
+                    off = index;
+                }
+                else
+                {
+                    off++;
                 }
-				else
-				{
-					off++;
-				}
                 continue;
             }
-			
+            
             /* A potential permissive URL autolink. */
             if(ch == _T(':')) {
                 static struct {
@@ -4006,78 +4006,78 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                 case '@':       /* Permissive e-mail autolink. */
                 case ':':       /* Permissive URL autolink. */
                 case '.':       /* Permissive WWW autolink. */
-				{
+                {
 
-					const MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
+                    const MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
 
-					const MD_MARK* closer = &ctx->marks[opener->next];
+                    const MD_MARK* closer = &ctx->marks[opener->next];
 
-					const CHAR* dest = STR(opener->end);
+                    const CHAR* dest = STR(opener->end);
 
-					SZ dest_size = closer->beg - opener->end;
+                    SZ dest_size = closer->beg - opener->end;
 
 
 
-					if (opener->ch == '@' || opener->ch == '.') {
+                    if (opener->ch == '@' || opener->ch == '.') {
 
-						dest_size += 7;
+                        dest_size += 7;
 
-						MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
+                        MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
 
-						memcpy(ctx->buffer,
+                        memcpy(ctx->buffer,
 
-							(opener->ch == '@' ? _T("mailto:") : _T("http://")),
+                            (opener->ch == '@' ? _T("mailto:") : _T("http://")),
 
-							7 * sizeof(CHAR));
+                            7 * sizeof(CHAR));
 
-						memcpy(ctx->buffer + 7, dest, (dest_size - 7) * sizeof(CHAR));
+                        memcpy(ctx->buffer + 7, dest, (dest_size - 7) * sizeof(CHAR));
 
-						dest = ctx->buffer;
+                        dest = ctx->buffer;
 
-					}
+                    }
 
 
 
-					MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
+                    MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
 
-						MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
+                        MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
 
-					break;
+                    break;
 
-				}
-				case '/':       /* Permissive Reddit autolinks */
-				{
-					MD_REDDIT_SLASH_DETAIL det;
-					if (CH(mark->beg) == '/')
-					{
-						det.name = ctx->text + mark->beg + 3;
-						det.size = mark->end - mark->beg - 3;
-						if (CH(mark->beg + 1) == 'r')
-						{
-							det.type = MD_REDDIT_SUBREDDIT;
-						}
-						else
-						{
-							det.type = MD_REDDIT_USER;
-						}
-					}
-					else // u/something or r/something instead of /r/something
-					{
-						det.name = ctx->text + mark->beg + 2;
-						det.size = mark->end - mark->beg - 2;
-						if (CH(mark->beg) == 'r')
-						{
-							det.type = MD_REDDIT_SUBREDDIT;
-						}
-						else
-						{
-							det.type = MD_REDDIT_USER;
-						}
-					}
-					MD_ENTER_SPAN(MD_REDDIT_SLASH_LINK, &det);
-					MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
-					MD_LEAVE_SPAN(MD_REDDIT_SLASH_LINK, &det);
-				}break;
+                }
+                case '/':       /* Permissive Reddit autolinks */
+                {
+                    MD_REDDIT_SLASH_DETAIL det;
+                    if (CH(mark->beg) == '/')
+                    {
+                        det.name = ctx->text + mark->beg + 3;
+                        det.size = mark->end - mark->beg - 3;
+                        if (CH(mark->beg + 1) == 'r')
+                        {
+                            det.type = MD_REDDIT_SUBREDDIT;
+                        }
+                        else
+                        {
+                            det.type = MD_REDDIT_USER;
+                        }
+                    }
+                    else // u/something or r/something instead of /r/something
+                    {
+                        det.name = ctx->text + mark->beg + 2;
+                        det.size = mark->end - mark->beg - 2;
+                        if (CH(mark->beg) == 'r')
+                        {
+                            det.type = MD_REDDIT_SUBREDDIT;
+                        }
+                        else
+                        {
+                            det.type = MD_REDDIT_USER;
+                        }
+                    }
+                    MD_ENTER_SPAN(MD_REDDIT_SLASH_LINK, &det);
+                    MD_TEXT(text_type, STR(mark->beg), mark->end - mark->beg);
+                    MD_LEAVE_SPAN(MD_REDDIT_SLASH_LINK, &det);
+                }break;
                 case '&':       /* Entity. */
                     MD_TEXT(MD_TEXT_ENTITY, STR(mark->beg), mark->end - mark->beg);
                     break;
diff --git a/md4c/md4c.h b/md4c/md4c.h
index e16bcf27..e8ff3087 100644
--- a/md4c/md4c.h
+++ b/md4c/md4c.h
@@ -132,7 +132,7 @@ typedef enum MD_SPANTYPE {
      * Note: Recognized only when MD_FLAG_STRIKETHROUGH is enabled.
      */
     MD_SPAN_DEL,
-	MD_REDDIT_SLASH_LINK
+    MD_REDDIT_SLASH_LINK
 } MD_SPANTYPE;
 
 /* Text is the actual textual contents of span. */
@@ -175,7 +175,7 @@ typedef enum MD_TEXTTYPE {
 } MD_TEXTTYPE;
 typedef enum MD_REDDIT_SLASH_TYPE
 {
-	MD_REDDIT_USER, MD_REDDIT_SUBREDDIT
+    MD_REDDIT_USER, MD_REDDIT_SUBREDDIT
 } MD_REDDIT_SLASH_TYPE;
 /* Alignment enumeration. */
 typedef enum MD_ALIGN {
@@ -250,9 +250,9 @@ typedef struct MD_SPAN_A_DETAIL {
 } MD_SPAN_A_DETAIL;
 typedef struct MD_REDDIT_SLASH_DETAIL
 {
-	MD_REDDIT_SLASH_TYPE type; //whether it's a user or subreddit
-	unsigned char size; 
-	MD_CHAR * name;
+    MD_REDDIT_SLASH_TYPE type; //whether it's a user or subreddit
+    unsigned char size; 
+    MD_CHAR * name;
 }MD_REDDIT_SLASH_DETAIL;
 /* Detailed info for MD_SPAN_IMG. */
 typedef struct MD_SPAN_IMG_DETAIL {
@@ -280,7 +280,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
 #define MD_FLAG_PERMISSIVEAUTOLINKS         (MD_FLAG_PERMISSIVEEMAILAUTOLINKS | MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEWWWAUTOLINKS)
 #define MD_FLAG_NOHTML                      (MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS)
 #define MD_FLAG_REDDITAUTOLINKS             0x8000  /* Enable Reddit autolinks */
-#define MD_FLAG_REDDIT_SLASHES_AS_LINKS        0x4000 //Instead of making Reddit links into special spans, make them into web links
+
 
 /* Convenient sets of flags corresponding to well-known Markdown dialects.
  * Note we may only support subset of features of the referred dialect.

From f1e5e0ee3c93215f0f6b716fbb7e90f716114722 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 16:39:24 -0700
Subject: [PATCH 11/17] rename Reddit dialect option to ensure consistency

---
 md4c/md4c.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/md4c/md4c.h b/md4c/md4c.h
index e8ff3087..aef3bdef 100644
--- a/md4c/md4c.h
+++ b/md4c/md4c.h
@@ -289,7 +289,7 @@ typedef struct MD_SPAN_IMG_DETAIL {
  */
 #define MD_DIALECT_COMMONMARK               0
 #define MD_DIALECT_GITHUB                   (MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_TABLES | MD_FLAG_STRIKETHROUGH)
-#define MD_DIALECT_REDDITPOST               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITAUTOLINKS | MD_FLAG_STRIKETHROUGH)
+#define MD_DIALECT_REDDIT               (MD_FLAG_PERMISSIVEATXHEADERS | MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_NOHTML | MD_FLAG_REDDITAUTOLINKS | MD_FLAG_STRIKETHROUGH)
 
 /* Renderer structure.
  */

From aff66bf520f47bbb563431a4d1a06dabb3326f60 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 16:52:04 -0700
Subject: [PATCH 12/17] change md2html flags

---
 md2html/md2html.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/md2html/md2html.c b/md2html/md2html.c
index a3fd660c..f7d02764 100644
--- a/md2html/md2html.c
+++ b/md2html/md2html.c
@@ -195,7 +195,7 @@ static const option cmdline_options[] = {
     { "version",                    'v', 'v', OPTION_ARG_NONE },
     { "commonmark",                  0,  'c', OPTION_ARG_NONE },
     { "github",                      0,  'g', OPTION_ARG_NONE },
-    { "reddit",                      0,  'R', OPTION_ARG_NONE },
+    { "reddit",                      0,  'r', OPTION_ARG_NONE },
     { "fverbatim-entities",          0,  'E', OPTION_ARG_NONE },
     { "fpermissive-atx-headers",     0,  'A', OPTION_ARG_NONE },
     { "fpermissive-url-autolinks",   0,  'U', OPTION_ARG_NONE },
@@ -209,7 +209,7 @@ static const option cmdline_options[] = {
     { "fcollapse-whitespace",        0,  'W', OPTION_ARG_NONE },
     { "ftables",                     0,  'T', OPTION_ARG_NONE },
     { "fstrikethrough",              0,  'S', OPTION_ARG_NONE },
-    { "freddit-autolinks",           0,  'r', OPTION_ARG_NONE },
+    { "freddit-autolinks",           0,  'R', OPTION_ARG_NONE },
     { 0 }
 };
 
@@ -293,7 +293,7 @@ cmdline_callback(int opt, char const* value, void* data)
 
         case 'c':   parser_flags = MD_DIALECT_COMMONMARK; break;
         case 'g':   parser_flags = MD_DIALECT_GITHUB; break;
-        case 'R':   parser_flags = MD_DIALECT_REDDITPOST; break;
+        case 'r':   parser_flags = MD_DIALECT_REDDITPOST; break;
 
         case 'E':   renderer_flags |= MD_RENDER_FLAG_VERBATIM_ENTITIES; break;
         case 'A':   parser_flags |= MD_FLAG_PERMISSIVEATXHEADERS; break;
@@ -308,7 +308,7 @@ cmdline_callback(int opt, char const* value, void* data)
         case 'V':   parser_flags |= MD_FLAG_PERMISSIVEAUTOLINKS; break;
         case 'T':   parser_flags |= MD_FLAG_TABLES; break;
         case 'S':   parser_flags |= MD_FLAG_STRIKETHROUGH; break;
-        case 'r':   parser_flags |= MD_FLAG_REDDITSLASHDETECTION;
+        case 'R':   parser_flags |= MD_FLAG_REDDITSLASHDETECTION; break;
 
         default:
             fprintf(stderr, "Illegal option: %s\n", value);

From 5233d98d183d246738eff9816eed7c1adddf43aa Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 18:09:07 -0700
Subject: [PATCH 13/17] add reddit autolinking to md2html and add tests

---
 test/reddit-autolinks.txt | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 test/reddit-autolinks.txt

diff --git a/test/reddit-autolinks.txt b/test/reddit-autolinks.txt
new file mode 100644
index 00000000..996e3199
--- /dev/null
+++ b/test/reddit-autolinks.txt
@@ -0,0 +1,22 @@
+
+# Reddit Autolinks
+
+With the flag `MD_FLAG_REDDITAUTOLINKS`, MD4C enables extension for recognition Reddit usernames and subreddits.
+
+For reference, here is snudown's (Reddit's markdown parser) implementation [link](https://github.com/reddit/snudown/blob/master/src/autolink.c).
+
+Reddit autolinks can be prefixed by a a forward slash or not: r/test and /r/test both work. A link ends when a non-alphanumeric character is hit. The only such character allowed it an underscore.
+
+```````````````````````````````` example
+Here is a link to /r/askreddit by u/me.
+.
+<p>Here is a link to <a href="https://www.reddit.com/r/askreddit">/r/askreddit</a> by <a href="https://www.reddit.com/u/me">u/me</a>.</p>
+````````````````````````````````
+
+A link can show up in the middle of the word if prefixed by a forward slash (you don't need a whitespace before).
+
+```````````````````````````````` example
+World/r/news vs /r/worldnew;s
+.
+<p>World<a href="https://www.reddit.com/r/news">/r/news</a> vs <a href="https://www.reddit.com/r/worldnew">/r/worldnew</a>;s</p>
+````````````````````````````````
\ No newline at end of file

From 70e8801ab12aeecad52f10cecd94b77bd5f46000 Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Mon, 8 Jan 2018 18:10:54 -0700
Subject: [PATCH 14/17] oops forgot to add some stuff to the last commit

---
 md2html/md2html.c     |  4 ++--
 md2html/render_html.c | 18 ++++++++++++++++++
 scripts/run-tests.sh  |  5 +++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/md2html/md2html.c b/md2html/md2html.c
index f7d02764..32c7ea65 100644
--- a/md2html/md2html.c
+++ b/md2html/md2html.c
@@ -293,7 +293,7 @@ cmdline_callback(int opt, char const* value, void* data)
 
         case 'c':   parser_flags = MD_DIALECT_COMMONMARK; break;
         case 'g':   parser_flags = MD_DIALECT_GITHUB; break;
-        case 'r':   parser_flags = MD_DIALECT_REDDITPOST; break;
+        case 'r':   parser_flags = MD_DIALECT_REDDIT; break;
 
         case 'E':   renderer_flags |= MD_RENDER_FLAG_VERBATIM_ENTITIES; break;
         case 'A':   parser_flags |= MD_FLAG_PERMISSIVEATXHEADERS; break;
@@ -308,7 +308,7 @@ cmdline_callback(int opt, char const* value, void* data)
         case 'V':   parser_flags |= MD_FLAG_PERMISSIVEAUTOLINKS; break;
         case 'T':   parser_flags |= MD_FLAG_TABLES; break;
         case 'S':   parser_flags |= MD_FLAG_STRIKETHROUGH; break;
-        case 'R':   parser_flags |= MD_FLAG_REDDITSLASHDETECTION; break;
+        case 'R':   parser_flags |= MD_FLAG_REDDITAUTOLINKS; break;
 
         default:
             fprintf(stderr, "Illegal option: %s\n", value);
diff --git a/md2html/render_html.c b/md2html/render_html.c
index 8f0b22c0..3ca58833 100644
--- a/md2html/render_html.c
+++ b/md2html/render_html.c
@@ -310,6 +310,22 @@ render_open_a_span(MD_RENDER_HTML* r, const MD_SPAN_A_DETAIL* det)
     RENDER_LITERAL(r, "\">");
 }
 
+static void
+render_reddit_link(MD_RENDER_HTML* r, const MD_REDDIT_SLASH_DETAIL* det)
+{
+    RENDER_LITERAL(r, "<a href=\"https://www.reddit.com/");
+    if (det->type == MD_REDDIT_SUBREDDIT)
+    {
+        RENDER_LITERAL(r, "r/");
+    }
+    else
+    {
+        RENDER_LITERAL(r, "u/");
+    }
+    render_text(r, det->name, det->size);
+    RENDER_LITERAL(r, "\">");
+}
+
 static void
 render_open_img_span(MD_RENDER_HTML* r, const MD_SPAN_IMG_DETAIL* det)
 {
@@ -413,6 +429,7 @@ enter_span_callback(MD_SPANTYPE type, void* detail, void* userdata)
         case MD_SPAN_IMG:       render_open_img_span(r, (MD_SPAN_IMG_DETAIL*) detail); break;
         case MD_SPAN_CODE:      RENDER_LITERAL(r, "<code>"); break;
         case MD_SPAN_DEL:       RENDER_LITERAL(r, "<del>"); break;
+        case MD_REDDIT_SLASH_LINK: render_reddit_link(r, (MD_REDDIT_SLASH_DETAIL*)detail); break;
     }
 
     return 0;
@@ -438,6 +455,7 @@ leave_span_callback(MD_SPANTYPE type, void* detail, void* userdata)
         case MD_SPAN_IMG:       /*noop, handled above*/ break;
         case MD_SPAN_CODE:      RENDER_LITERAL(r, "</code>"); break;
         case MD_SPAN_DEL:       RENDER_LITERAL(r, "</del>"); break;
+        case MD_REDDIT_SLASH_LINK: RENDER_LITERAL(r, "</a>"); break;
     }
 
     return 0;
diff --git a/scripts/run-tests.sh b/scripts/run-tests.sh
index cc62111b..f5f45e23 100755
--- a/scripts/run-tests.sh
+++ b/scripts/run-tests.sh
@@ -54,6 +54,11 @@ echo
 echo "Strikethrough extension:"
 $PYTHON "$TEST_DIR/spec_tests.py" -s "$TEST_DIR/strikethrough.txt" -p "$PROGRAM --fstrikethrough"
 
+echo
+echo "Reddit autolinks extension:"
+$PYTHON "$TEST_DIR/spec_tests.py" -s
+"$TEST_DIR/reddit-autolinks.txt" -p "$PROGRAM --freddit-autolinks"
+
 echo
 echo "Pathological input:"
 $PYTHON "$TEST_DIR/pathological_tests.py" -p "$PROGRAM"

From 061d6f6dfd52b9bcb7dfc96eb79ed6c3e4e7749f Mon Sep 17 00:00:00 2001
From: Jimmy <jimmyjxiao@outlook.com>
Date: Thu, 11 Jan 2018 16:40:33 -0700
Subject: [PATCH 15/17] remove extra linebreak in tests

---
 scripts/run-tests.sh | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/scripts/run-tests.sh b/scripts/run-tests.sh
index f5f45e23..632119ae 100755
--- a/scripts/run-tests.sh
+++ b/scripts/run-tests.sh
@@ -56,8 +56,7 @@ $PYTHON "$TEST_DIR/spec_tests.py" -s "$TEST_DIR/strikethrough.txt" -p "$PROGRAM
 
 echo
 echo "Reddit autolinks extension:"
-$PYTHON "$TEST_DIR/spec_tests.py" -s
-"$TEST_DIR/reddit-autolinks.txt" -p "$PROGRAM --freddit-autolinks"
+$PYTHON "$TEST_DIR/spec_tests.py" -s "$TEST_DIR/reddit-autolinks.txt" -p "$PROGRAM --freddit-autolinks"
 
 echo
 echo "Pathological input:"

From 3fb5f0385f46dacd5b5e13b6e439eb16615fb18c Mon Sep 17 00:00:00 2001
From: Jimmy <jimmyjxiao@outlook.com>
Date: Thu, 11 Jan 2018 16:45:43 -0700
Subject: [PATCH 16/17] remove extra linebreaks

---
 md4c/md4c.c | 24 +-----------------------
 1 file changed, 1 insertion(+), 23 deletions(-)

diff --git a/md4c/md4c.c b/md4c/md4c.c
index 4f667889..6f9bebd5 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -4007,43 +4007,21 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                 case ':':       /* Permissive URL autolink. */
                 case '.':       /* Permissive WWW autolink. */
                 {
-
                     const MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
-
                     const MD_MARK* closer = &ctx->marks[opener->next];
-
                     const CHAR* dest = STR(opener->end);
-
                     SZ dest_size = closer->beg - opener->end;
-
-
-
                     if (opener->ch == '@' || opener->ch == '.') {
-
                         dest_size += 7;
-
                         MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
-
                         memcpy(ctx->buffer,
-
                             (opener->ch == '@' ? _T("mailto:") : _T("http://")),
-
                             7 * sizeof(CHAR));
-
                         memcpy(ctx->buffer + 7, dest, (dest_size - 7) * sizeof(CHAR));
-
                         dest = ctx->buffer;
-
                     }
-
-
-
-                    MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
-
-                        MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
-
+                    MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER), MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
                     break;
-
                 }
                 case '/':       /* Permissive Reddit autolinks */
                 {

From c959ac7c12749a44c8ed6398625a061a254bb91c Mon Sep 17 00:00:00 2001
From: Jimmy Xiao <jimmyjxiao@outlook.com>
Date: Thu, 11 Jan 2018 18:07:49 -0700
Subject: [PATCH 17/17] Update README.md

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 65c443c5..93ad5bcf 100644
--- a/README.md
+++ b/README.md
@@ -105,7 +105,7 @@ some extensions or allowing some deviations from the specification.
  * With the flag `MD_FLAG_NOINDENTEDCODEBLOCKS`, indented code blocks are
    disabled.
    
- * With the flag `MD_FLAG_REDDITSLASHDETECTION`, Reddit subreddit and user links such as r/test or /u/me are detected
+ * With the flag `MD_FLAG_REDDITAUTOLINKS`, Reddit subreddit and user links such as r/test or /u/me are detected
 
 
 ## Input/Output Encoding