Expand embedded latex to support $$ .. $$, \[ .. \], and \( .. \) escapes

generate.c

@@ -1208,18 +1208,23 @@ smartypants(int c, int *flags, MMIOT *f)
 
 
 #if WITH_LATEX
-/* process latex with \(, \) delimiters
+/* process latex with arbitrary 2-character ( $$ .. $$, \[ .. \], \( .. \)
+ * delimiters
  */
 static int
-mathhandler(MMIOT *f, int endtick) {
-    int i = 0, size;
+mathhandler(MMIOT *f, int e1, e2)
+{
+    int i = 0;
 
-    while(peek(f, ++i) != EOF)
-        if (peek(f, i) == '\\' && peek(f, i+1) == endtick) {
-            Qstring("\\(", f);
-            while(i-->-1) cputc(pull(f), f);
+    while(peek(f, ++i) != EOF) {
+        if (peek(f, i) == e1 && peek(f, i+1) == e2) {
+	    cputc(peek(f,-1), f);
+	    cputc(peek(f, 0), f);
+	    while ( i-- > -1 )
+		cputc(pull(f), f);
             return 1;
         }
+    }
     return 0;
 }
 #endif
@@ -1406,7 +1411,8 @@ text(MMIOT *f)
 				break;
 
 #if WITH_LATEX
-		    case '(':   if ( mathhandler(f, ')') )
+		    case '[':
+		    case '(':   if ( mathhandler(f, '\\', (c =='(')?')':']') )
 				    break;
 				/* else fall through to default */
 #endif
@@ -1436,6 +1442,13 @@ text(MMIOT *f)
 			Qchar(c, f);
 		    break;
 
+#if WITH_LATEX
+	case '$':   if ( ((c = pull(f)) == '$') && mathhandler(f, '$', '$') )
+			break;
+		    Qchar('$', f);
+		    /* fall through to default */
+#endif
+	
 	default:    Qchar(c, f);
 		    break;
 	}

tests/latex.t

@@ -12,5 +12,8 @@ try 'latex passthrough' '\(\tex\)' '<p>\(\tex\)</p>'
 try 'latex w/ special characters' 'Equation:\(a<+>b\).' \
     '<p>Equation:\(a&lt;+&gt;b\).</p>'
 
+try 'latex with $$ .. $$' '$$foo$$' '<p>$$foo$$</p>'
+try 'latex with \[ .. \]' '\[foo\]' '<p>\[foo\]</p>'
+
 summary $0
 exit $rc

tests/linkylinky.t

@@ -10,7 +10,14 @@ try 'url contains +' '[hehehe](u+rl)' '<p><a href="u+rl">hehehe</a></p>'
 try 'url contains "' '[hehehe](u"rl)' '<p><a href="u%22rl">hehehe</a></p>'
 try 'url contains <' '[hehehe](u<rl)' '<p><a href="u&lt;rl">hehehe</a></p>'
 try 'url contains whitespace' '[ha](r u)' '<p><a href="r%20u">ha</a></p>'
-try 'label contains escaped []s' '[a\[b\]c](d)' '<p><a href="d">a[b]c</a></p>'
+
+# latex collides with this test
+if ./markdown -V | grep LATEX >/dev/null; then
+    RESULT='<p><a href="d">a\[b\]c</a></p>'
+else
+    RESULT='<p><a href="d">a[b]c</a></p>'
+fi
+try 'label contains escaped []s' '[a\[b\]c](d)' "$RESULT"
 
 try '<label> w/o title' '[hello](<sailor>)' '<p><a href="sailor">hello</a></p>'
 try '<label> with title' '[hello](<sailor> "boy")' '<p><a href="sailor" title="boy">hello</a></p>'