Fix buffer underflow (Issue #338)

Author: michaelrsweet

CHANGES.md

@@ -7,6 +7,7 @@
 - Added support for dc:subject and dc:language metadata in EPUB output from the
   HTML keywords and lang values.
 - Added support for the subject and language metadata in markdown input.
+- Fixed a buffer underflow bug (Issue #338)
 
 
 # Changes in HTMLDOC v1.9.4

htmldoc/ps-pdf.cxx

@@ -5188,7 +5188,7 @@ parse_paragraph(tree_t *t,	/* I - Tree to parse */
             linewidth  += temp_width;
             lineptr    += strlen((char *)lineptr);
 
-            if (lineptr[-1] == ' ')
+            if (lineptr > line && lineptr[-1] == ' ')
               whitespace = 1;
             else
               whitespace = 0;