From: Alex Lam S.L <alexlamsl@gmail.com>
Date: Sat, 3 Feb 2018 19:58:49 +0000 (+0800)
Subject: maintain order between side-effects and externally observable assignments (#2879)
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=78a44d5ab0fd2195c8f22cc8a39193b33dad6188;p=UglifyJS.git

maintain order between side-effects and externally observable assignments (#2879)

fixes #2878
---

diff --git a/lib/compress.js b/lib/compress.js
index 993092a0..f9cd7a41 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1040,7 +1040,6 @@ merge(Compressor.prototype, {
                     || node instanceof AST_PropAccess
                         && (side_effects || node.expression.may_throw_on_access(compressor))
                     || node instanceof AST_SymbolRef
-                        && !(parent instanceof AST_Assign && parent.operator == "=" && parent.left === node)
                         && (lvalues[node.name] || side_effects && may_modify(node))
                     || node instanceof AST_VarDef && node.value
                         && (node.name.name in lvalues || side_effects && may_modify(node.name))
diff --git a/test/compress/collapse_vars.js b/test/compress/collapse_vars.js
index ad09edc3..4191de85 100644
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -4433,3 +4433,37 @@ issue_2873_2: {
     }
     expect_stdout: "0 1"
 }
+
+issue_2878: {
+    options = {
+        collapse_vars: true,
+        sequences: true,
+    }
+    input: {
+        var c = 0;
+        (function (a, b) {
+            function f2() {
+                if (a) c++;
+            }
+            b = f2();
+            a = 1;
+            b && b.b;
+            f2();
+        })();
+        console.log(c);
+    }
+    expect: {
+        var c = 0;
+        (function (a, b) {
+            function f2() {
+                if (a) c++;
+            }
+            b = f2(),
+            a = 1,
+            b && b.b,
+            f2();
+        })(),
+        console.log(c);
+    }
+    expect_stdout: "1"
+}