Implement flag MD_FLAG_SKIPBOM on parser side.

Also update md2html to enable this on the parser side rather than
renderer side.

Make MD_HTML_FLAG_SKIP_UTF8_BOM deprecated. md_html() converts the flag
into parser_flags.

Author: mity

md2html/md2html.c

@@ -34,12 +34,8 @@
 
 
 /* Global options. */
-static unsigned parser_flags = 0;
-#ifndef MD4C_USE_ASCII
-    static unsigned renderer_flags = MD_HTML_FLAG_DEBUG | MD_HTML_FLAG_SKIP_UTF8_BOM;
-#else
-    static unsigned renderer_flags = MD_HTML_FLAG_DEBUG;
-#endif
+static unsigned parser_flags = MD_FLAG_SKIPBOM;
+static unsigned renderer_flags = MD_HTML_FLAG_DEBUG;
 static int want_fullhtml = 0;
 static int want_xhtml = 0;
 static int want_stat = 0;

src/md4c-html.c

@@ -553,14 +553,9 @@ md_html(const MD_CHAR* input, MD_SIZE input_size,
             render.escape_map[i] |= NEED_URL_ESC_FLAG;
     }
 
-    /* Consider skipping UTF-8 byte order mark (BOM). */
-    if(renderer_flags & MD_HTML_FLAG_SKIP_UTF8_BOM  &&  sizeof(MD_CHAR) == 1) {
-        static const MD_CHAR bom[3] = { (char)0xef, (char)0xbb, (char)0xbf };
-        if(input_size >= sizeof(bom)  &&  memcmp(input, bom, sizeof(bom)) == 0) {
-            input += sizeof(bom);
-            input_size -= sizeof(bom);
-        }
-    }
+    /* For compatibility with old apps. */
+    if(renderer_flags & MD_HTML_FLAG_SKIP_UTF8_BOM)
+        parser.flags |= MD_FLAG_SKIPBOM;
 
     return md_parse(input, input_size, &parser, (void*) &render);
 }

src/md4c-html.h

@@ -36,7 +36,7 @@
 /* If set, debug output from md_parse() is sent to stderr. */
 #define MD_HTML_FLAG_DEBUG                  0x0001
 #define MD_HTML_FLAG_VERBATIM_ENTITIES      0x0002
-#define MD_HTML_FLAG_SKIP_UTF8_BOM          0x0004
+#define MD_HTML_FLAG_SKIP_UTF8_BOM          0x0004  /* Deprecated; use MD_FLAG_SKIPBOM on the parser side in new code. */
 #define MD_HTML_FLAG_XHTML                  0x0008
 
 

src/md4c.c

@@ -6468,6 +6468,21 @@ md_parse(const MD_CHAR* text, MD_SIZE size, const MD_PARSER* parser, void* userd
     memcpy(&ctx.parser, parser, parser_size);
     memset((uint8_t*)&ctx.parser + parser_size, 0, sizeof(ctx.parser) - parser_size);
 
+#if defined MD4C_USE_UTF8  ||  defined MD4C_USE_UTF16
+    if(parser->flags & MD_FLAG_SKIPBOM) {
+#ifdef MD4C_USE_UTF8
+        static const MD_CHAR bom[3] = { (char)0xef, (char)0xbb, (char)0xbf };
+#endif
+#ifdef MD4C_USE_UTF16
+        static const MD_CHAR bom[1] = { (WCHAR)0xfeff };
+#endif
+        if(size >= SIZEOF_ARRAY(bom)  &&  memcmp(text, bom, sizeof(bom)) == 0) {
+            text += SIZEOF_ARRAY(bom);
+            size -= SIZEOF_ARRAY(bom);
+        }
+    }
+#endif
+
     ctx.text = text;
     ctx.size = size;
     ctx.userdata = userdata;

src/md4c.h

@@ -303,21 +303,23 @@ typedef struct MD_SPAN_WIKILINK {
  * By default (when MD_PARSER::flags == 0), we follow CommonMark specification.
  * The following flags may allow some extensions or deviations from it.
  */
-#define MD_FLAG_COLLAPSEWHITESPACE          0x0001  /* In MD_TEXT_NORMAL, collapse non-trivial whitespace into single ' ' */
-#define MD_FLAG_PERMISSIVEATXHEADERS        0x0002  /* Do not require space in ATX headers ( ###header ) */
-#define MD_FLAG_PERMISSIVEURLAUTOLINKS      0x0004  /* Recognize URLs as autolinks even without '<', '>' */
-#define MD_FLAG_PERMISSIVEEMAILAUTOLINKS    0x0008  /* Recognize e-mails as autolinks even without '<', '>' and 'mailto:' */
-#define MD_FLAG_NOINDENTEDCODEBLOCKS        0x0010  /* Disable indented code blocks. (Only fenced code works.) */
-#define MD_FLAG_NOHTMLBLOCKS                0x0020  /* Disable raw HTML blocks. */
-#define MD_FLAG_NOHTMLSPANS                 0x0040  /* Disable raw HTML (inline). */
-#define MD_FLAG_TABLES                      0x0100  /* Enable tables extension. */
-#define MD_FLAG_STRIKETHROUGH               0x0200  /* Enable strikethrough extension. */
-#define MD_FLAG_PERMISSIVEWWWAUTOLINKS      0x0400  /* Enable WWW autolinks (even without any scheme prefix, if they begin with 'www.') */
-#define MD_FLAG_TASKLISTS                   0x0800  /* Enable task list extension. */
-#define MD_FLAG_LATEXMATHSPANS              0x1000  /* Enable $ and $$ containing LaTeX equations. */
-#define MD_FLAG_WIKILINKS                   0x2000  /* Enable wiki links extension. */
-#define MD_FLAG_UNDERLINE                   0x4000  /* Enable underline extension (and disables '_' for normal emphasis). */
-#define MD_FLAG_HARD_SOFT_BREAKS            0x8000  /* Force all soft breaks to act as hard breaks. */
+#define MD_FLAG_COLLAPSEWHITESPACE          0x00000001  /* In MD_TEXT_NORMAL, collapse non-trivial whitespace into single ' ' */
+#define MD_FLAG_PERMISSIVEATXHEADERS        0x00000002  /* Do not require space in ATX headers ( ###header ) */
+#define MD_FLAG_PERMISSIVEURLAUTOLINKS      0x00000004  /* Recognize URLs as autolinks even without '<', '>' */
+#define MD_FLAG_PERMISSIVEEMAILAUTOLINKS    0x00000008  /* Recognize e-mails as autolinks even without '<', '>' and 'mailto:' */
+#define MD_FLAG_NOINDENTEDCODEBLOCKS        0x00000010  /* Disable indented code blocks. (Only fenced code works.) */
+#define MD_FLAG_NOHTMLBLOCKS                0x00000020  /* Disable raw HTML blocks. */
+#define MD_FLAG_NOHTMLSPANS                 0x00000040  /* Disable raw HTML (inline). */
+#define MD_FLAG_TABLES                      0x00000100  /* Enable tables extension. */
+#define MD_FLAG_STRIKETHROUGH               0x00000200  /* Enable strikethrough extension. */
+#define MD_FLAG_PERMISSIVEWWWAUTOLINKS      0x00000400  /* Enable WWW autolinks (even without any scheme prefix, if they begin with 'www.') */
+#define MD_FLAG_TASKLISTS                   0x00000800  /* Enable task list extension. */
+#define MD_FLAG_LATEXMATHSPANS              0x00001000  /* Enable $ and $$ containing LaTeX equations. */
+#define MD_FLAG_WIKILINKS                   0x00002000  /* Enable wiki links extension. */
+#define MD_FLAG_UNDERLINE                   0x00004000  /* Enable underline extension (and disables '_' for normal emphasis). */
+#define MD_FLAG_HARD_SOFT_BREAKS            0x00008000  /* Force all soft breaks to act as hard breaks. */
+#define MD_FLAG_SKIPBOM                     0x00010000  /* Skip Unicode BOM, if present. */
+
 
 #define MD_FLAG_PERMISSIVEAUTOLINKS         (MD_FLAG_PERMISSIVEEMAILAUTOLINKS | MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEWWWAUTOLINKS)
 #define MD_FLAG_NOHTML                      (MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS)