shithub: libmujs

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Fix creation of empty regular expressions.

Handle empty regular expressions in RegExp compiler asserts.

Also turn them into /(?:)/ on the JS side, so they can be printed
back as valid JS syntax where // is a comment, not a regular expression.

--- a/jsregexp.c

+++ b/jsregexp.c

@@ -116,12 +116,15 @@

 		pattern = old->source;

 		flags = old->flags;

 	} else if (js_isundefined(J, 1)) {

-		pattern = "";

+		pattern = "(?:)";

 		flags = 0;

 	} else {

 		pattern = js_tostring(J, 1);

 		flags = 0;

 	}

+

+	if (strlen(pattern) == 0)

+		pattern = "(?:)";

 	if (js_isdefined(J, 2)) {

 		const char *s = js_tostring(J, 2);

--- a/regexp.c

+++ b/regexp.c

@@ -831,9 +831,12 @@

 	g.prog = alloc(ctx, NULL, sizeof (Reprog));

 	if (!g.prog)

 		die(&g, "cannot allocate regular expression");

-	g.pstart = g.pend = alloc(ctx, NULL, sizeof (Renode) * strlen(pattern) * 2);

-	if (!g.pstart)

-		die(&g, "cannot allocate regular expression parse list");

+	n = strlen(pattern) * 2;

+	if (n > 0) {

+		g.pstart = g.pend = alloc(ctx, NULL, sizeof (Renode) * n);

+		if (!g.pstart)

+			die(&g, "cannot allocate regular expression parse list");

+	}

 	g.source = pattern;

 	g.ncclass = 0;