fix `mangle` name collision across files (#2722)

1 files changed, 14 insertions, 11 deletions

diff --git a/lib/propmangle.js b/lib/propmangle.js
index c2f27c42..ffc8faf8 100644
--- a/lib/propmangle.js
+++ b/lib/propmangle.js
@@ -110,12 +110,15 @@ function mangle_properties(ast, options) {
     if (!Array.isArray(reserved)) reserved = [];
     if (!options.builtins) find_builtins(reserved);
 
-    var cache = options.cache;
-    if (cache == null) {
-        cache = {
-            cname: -1,
-            props: new Dictionary()
-        };
+    var cname = -1;
+    var cache;
+    if (options.cache) {
+        cache = options.cache.props;
+        cache.each(function(mangled_name) {
+            push_uniq(reserved, mangled_name);
+        });
+    } else {
+        cache = new Dictionary();
     }
 
     var regex = options.regex;
@@ -172,7 +175,7 @@ function mangle_properties(ast, options) {
         if (unmangleable.indexOf(name) >= 0) return false;
         if (reserved.indexOf(name) >= 0) return false;
         if (options.only_cache) {
-            return cache.props.has(name);
+            return cache.has(name);
         }
         if (/^-?[0-9]+(\.[0-9]+)?(e[+-][0-9]+)?$/.test(name)) return false;
         return true;
@@ -181,7 +184,7 @@ function mangle_properties(ast, options) {
     function should_mangle(name) {
         if (regex && !regex.test(name)) return false;
         if (reserved.indexOf(name) >= 0) return false;
-        return cache.props.has(name)
+        return cache.has(name)
             || names_to_mangle.indexOf(name) >= 0;
     }
 
@@ -199,7 +202,7 @@ function mangle_properties(ast, options) {
             return name;
         }
 
-        var mangled = cache.props.get(name);
+        var mangled = cache.get(name);
         if (!mangled) {
             if (debug) {
                 // debug mode: use a prefix and suffix to preserve readability, e.g. o.foo -> o._$foo$NNN_.
@@ -213,11 +216,11 @@ function mangle_properties(ast, options) {
             // either debug mode is off, or it is on and we could not use the mangled name
             if (!mangled) {
                 do {
-                    mangled = base54(++cache.cname);
+                    mangled = base54(++cname);
                 } while (!can_mangle(mangled));
             }
 
-            cache.props.set(name, mangled);
+            cache.set(name, mangled);
         }
         return mangled;
     }