Fix conflict in parsing permissive autolinks and ordinary links.

The issues is caused by the fact that we do not know exact position of permissive auto-link in time of md_collect_marks() because there is no syntax to mark its end on the 1st place. This causes that eventually, the closer mark in ctx->marks[] can be out-of-order somewhat. As a consequence, if some other mark range (e.g. ordinary link) shadows the auto-link, the closer mark may be left outside the shadowed range and survive till the phase when we generate the output. We fix by using an extra mark flag to remember we did really output the opener mark, and output the closer only in such case. Fixes mity#53.
ec1oud · Apr 17, 2019 · 5d2f663 · 5d2f663
1 parent c2693fd
commit 5d2f663
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diff --git a/md4c/md4c.c b/md4c/md4c.c
@@ -2497,6 +2497,7 @@ struct MD_MARK_tag {
 #define MD_MARK_EMPH_MODULO3_2              (0x40 | 0x80)
 #define MD_MARK_EMPH_MODULO3_MASK           (0x40 | 0x80)
 #define MD_MARK_AUTOLINK                    0x20  /* Distinguisher for '<', '>'. */
+#define MD_MARK_VALIDPERMISSIVEAUTOLINK     0x20  /* For permissive autolinks. */
 
 
 static MD_MARK*
@@ -3988,11 +3989,20 @@ 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];
+                    MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
+                    MD_MARK* closer = &ctx->marks[opener->next];
                     const CHAR* dest = STR(opener->end);
                     SZ dest_size = closer->beg - opener->end;
 
+                    /* For permissive auto-links we do not know closer mark
+                     * position at the time of md_collect_marks(), therefore
+                     * it can be out-of-order in ctx->marks[].
+                     *
+                     * With this flag, we make sure that we output the closer
+                     * only if we processed the opener. */
+                    if(mark->flags & MD_MARK_OPENER)
+                        closer->flags |= MD_MARK_VALIDPERMISSIVEAUTOLINK;
+
                     if(opener->ch == '@' || opener->ch == '.') {
                         dest_size += 7;
                         MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
@@ -4003,8 +4013,9 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                         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));
+                    if(closer->flags & MD_MARK_VALIDPERMISSIVEAUTOLINK)
+                        MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
+                                    MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
                     break;
                 }
 

diff --git a/test/permissive-url-autolinks.txt b/test/permissive-url-autolinks.txt
@@ -62,3 +62,18 @@ Anonymous FTP is available at ftp://foo.bar.baz.
 <p>(Visit <a href="https://encrypted.google.com/search?q=Markup+(business)">https://encrypted.google.com/search?q=Markup+(business)</a>)</p>
 <p>Anonymous FTP is available at <a href="ftp://foo.bar.baz">ftp://foo.bar.baz</a>.</p>
 ````````````````````````````````
+
+
+## GitHub Issues
+
+### [Issue 53](https://github.com/mity/md4c/issues/53)
+```````````````````````````````` example
+This is [link](http://github.com/).
+.
+<p>This is <a href="http://github.com/">link</a>.</p>
+````````````````````````````````
+```````````````````````````````` example
+This is [link](http://github.com/)X
+.
+<p>This is <a href="http://github.com/">link</a>X</p>
+````````````````````````````````
diff --git a/test/permissive-www-autolinks.txt b/test/permissive-www-autolinks.txt
@@ -90,3 +90,18 @@ www.commonmark.org/he<lp
 .
 <p><a href="http://www.commonmark.org/he">www.commonmark.org/he</a>&lt;lp</p>
 ````````````````````````````````
+
+
+## GitHub Issues
+
+### [Issue 53](https://github.com/mity/md4c/issues/53)
+```````````````````````````````` example
+This is [link](www.github.com/).
+.
+<p>This is <a href="www.github.com/">link</a>.</p>
+````````````````````````````````
+```````````````````````````````` example
+This is [link](www.github.com/)X
+.
+<p>This is <a href="www.github.com/">link</a>X</p>
+````````````````````````````````