fix: find the *last* sourceMappingURL in the source document.

This fixes odd behaviour for source files that contain the literal string
'//# sourceMappingURL=' somewhere in the actual source code.

Author: mprobst

source-map-support.js

@@ -72,9 +72,13 @@ function retrieveSourceMapURL(source) {
 
   // Get the URL of the source map
   fileData = retrieveFile(source);
-  var match = /\/\/[#@]\s*sourceMappingURL=([^'"]+)\s*$/m.exec(fileData);
-  if (!match) return null;
-  return match[1];
+  var re = /\/\/[#@]\s*sourceMappingURL=([^'"]+)\s*$/mg;
+  // Keep executing the search to find the *last* sourceMappingURL to avoid
+  // picking up sourceMappingURLs from comments, strings, etc.
+  var lastMatch, match;
+  while (match = re.exec(fileData)) lastMatch = match;
+  if (!lastMatch) return null;
+  return lastMatch[1];
 };
 
 // Can be overridden by the retrieveSourceMap option to install. Takes a

test.js

@@ -250,6 +250,16 @@ it('sourcesContent with data URL', function() {
   ]);
 });
 
+it('finds the last sourceMappingURL', function() {
+  compareStackTrace(createMultiLineSourceMapWithSourcesContent(), [
+    '//# sourceMappingURL=missing.map.js',  // NB: compareStackTrace adds another source mapping.
+    'throw new Error("test");'
+  ], [
+    'Error: test',
+    /^    at Object\.exports\.test \(.*\/original.js:1002:5\)$/
+  ]);
+});
+
 it('default options', function(done) {
   compareStdout(done, createSingleLineSourceMap(), [
     '',