improve source map handling (#3464)

fixes #2947
fixes #3277
fixes #3411

1 files changed, 34 insertions, 15 deletions

diff --git a/lib/minify.js b/lib/minify.js
index 9eebc373..93f1295e 100644
--- a/lib/minify.js
+++ b/lib/minify.js
@@ -1,19 +1,39 @@
 "use strict";
 
-var to_ascii = typeof atob == "undefined" ? function(b64) {
-    return new Buffer(b64, "base64").toString();
-} : atob;
-var to_base64 = typeof btoa == "undefined" ? function(str) {
-    return new Buffer(str).toString("base64");
-} : btoa;
+var to_ascii, to_base64;
+if (typeof Buffer == "undefined") {
+    to_ascii = atob;
+    to_base64 = btoa;
+} else if (typeof Buffer.alloc == "undefined") {
+    to_ascii = function(b64) {
+        return new Buffer(b64, "base64").toString();
+    };
+    to_base64 = function(str) {
+        return new Buffer(str).toString("base64");
+    };
+} else {
+    to_ascii = function(b64) {
+        return Buffer.from(b64, "base64").toString();
+    };
+    to_base64 = function(str) {
+        return Buffer.from(str).toString("base64");
+    };
+}
 
-function read_source_map(name, code) {
-    var match = /\n\/\/# sourceMappingURL=data:application\/json(;.*?)?;base64,(\S+)\s*$/.exec(code);
-    if (!match) {
-        AST_Node.warn("inline source map not found: " + name);
-        return null;
+function read_source_map(name, toplevel) {
+    var comments = toplevel.end.comments_after;
+    for (var i = comments.length; --i >= 0;) {
+        var comment = comments[i];
+        if (comment.type != "comment1") break;
+        var match = /^# ([^\s=]+)=(\S+)\s*$/.exec(comment.value);
+        if (!match) break;
+        if (match[1] == "sourceMappingURL") {
+            match = /^data:application\/json(;.*?)?;base64,(\S+)$/.exec(match[2]);
+            if (!match) break;
+            return to_ascii(match[2]);
+        }
     }
-    return to_ascii(match[2]);
+    AST_Node.warn("inline source map not found: " + name);
 }
 
 function parse_source_map(content) {
@@ -134,10 +154,10 @@ function minify(files, options) {
             source_maps = source_map_content && Object.create(null);
             for (var name in files) if (HOP(files, name)) {
                 options.parse.filename = name;
-                options.parse.toplevel = parse(files[name], options.parse);
+                options.parse.toplevel = toplevel = parse(files[name], options.parse);
                 if (source_maps) {
                     if (source_map_content == "inline") {
-                        var inlined_content = read_source_map(name, files[name]);
+                        var inlined_content = read_source_map(name, toplevel);
                         if (inlined_content) {
                             source_maps[name] = parse_source_map(inlined_content);
                         }
@@ -146,7 +166,6 @@ function minify(files, options) {
                     }
                 }
             }
-            toplevel = options.parse.toplevel;
         }
         if (quoted_props) {
             reserve_quoted_keys(toplevel, quoted_props);