don't assume transform functions don't mutate AST arrays. Closes #1351

terser · Feb 23, 2023 · fa6f164 · fa6f164
1 parent 3c9fc4c
commit fa6f164
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Showing 2 changed files with 49 additions and 24 deletions.
diff --git a/lib/utils/index.js b/lib/utils/index.js
@@ -99,36 +99,20 @@ function return_null() { return null; }
 
 var MAP = (function() {
     function MAP(a, tw, allow_splicing = true) {
-        // Loop but try not to build a new array
+        const new_a = [];
+
         for (let i = 0; i < a.length; ++i) {
             let item = a[i];
             let ret = item.transform(tw, allow_splicing);
 
-            if (ret !== item) {
-                const a1 = a.slice(0, i);
-
-                // Looks like something was transformed. Change the loop.
-                if (ret instanceof AST_Node) {
-                    a1.push(ret);
-                } else if (ret instanceof Splice) {
-                    a1.push(...ret.v);
-                }
-
-                while ((item = a[++i])) {
-                    const ret = item.transform(tw, true);
-
-                    if (ret instanceof AST_Node) {
-                        a1.push(ret);
-                    } else if (ret instanceof Splice) {
-                        a1.push(...ret.v);
-                    }
-                }
-
-                return a1;
+            if (ret instanceof AST_Node) {
+                new_a.push(ret);
+            } else if (ret instanceof Splice) {
+                new_a.push(...ret.v);
             }
         }
 
-        return a;
+        return new_a;
     }
 
     MAP.splice = function(val) { return new Splice(val); };

diff --git a/test/compress/join-vars.js b/test/compress/join-vars.js
@@ -37,4 +37,45 @@ issue_1079_with_mixed: {
         var netmaskBinary = ''
         for (let i = 0; i < netmaskBits; ++i) netmaskBinary += '1';
     }
-}
+}
+
+join_vars_lose_other_var: {
+    options = {
+        defaults: false,
+        inline: true,
+        reduce_vars: true,
+        unused: true,
+        side_effects: true,
+        join_vars: true,
+    }
+    input: {
+        global.exports = {
+            set a(a) {
+                console.log(a().get_b())
+                const incremented = a()
+                incremented.inc_b()
+                console.log(incremented.get_b())
+            }
+        };
+
+        (function (factory) {
+            factory(exports)
+        })((function (exports) {
+            exports.a = function () {
+                var b = "PASS",
+                    _this = {};
+                _this.get_b = function () {
+                    return b;
+                }
+                _this.inc_b = function () {
+                    b += "PASS";
+                }
+                return _this;
+            };
+        }));
+    }
+    expect_stdout: [
+      "PASS",
+      "PASSPASS"
+    ]
+}