3 files changed, 30 insertions, 6 deletions
diff --git a/test/compress/collapse_vars.js b/test/compress/collapse_vars.js
index 66190e3e..30dc0248 100644
--- a/test/compress/collapse_vars.js
+++ b/test/compress/collapse_vars.js
@@ -4658,6 +4658,7 @@ replace_all_var_scope: {
     rename = true
     options = {
         collapse_vars: true,
+        reduce_vars: true,
         unused: true,
     }
     mangle = {}
@@ -4676,7 +4677,7 @@ replace_all_var_scope: {
         (function(c, o) {
             switch (~a) {
               case (b += a):
-              case o++:
+              case +o:
             }
         })(--b, a);
         console.log(a, b);
@@ -4728,7 +4729,7 @@ cascade_statement: {
         }
         function f3(a, b) {
             for (; a < b; a++)
-                if (c = a, a && b)
+                if ((c = a) && b)
                     var c = c = b(a);
         }
     }
diff --git a/test/compress/destructured.js b/test/compress/destructured.js
index 41e337be..140d48e1 100644
--- a/test/compress/destructured.js
+++ b/test/compress/destructured.js
@@ -2625,3 +2625,25 @@ issue_4994: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_5017: {
+    options = {
+        collapse_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+    }
+    input: {
+        var a = function() {};
+        var b = c = a;
+        var c = [ c ] = [ c ];
+        console.log(c[0] === a ? "PASS" : "FAIL");
+    }
+    expect: {
+        var a = function() {};
+        var b = a;
+        var c = [ c ] = [ c = a ];
+        console.log(c[0] === a ? "PASS" : "FAIL");
+    }
+    expect_stdout: "PASS"
+    node_version: ">=6"
+}
diff --git a/test/compress/keep_fargs.js b/test/compress/keep_fargs.js
index 8761c330..3c2e4a74 100644
--- a/test/compress/keep_fargs.js
+++ b/test/compress/keep_fargs.js
@@ -1151,6 +1151,7 @@ replace_all_var_scope: {
     options = {
         collapse_vars: true,
         keep_fargs: false,
+        reduce_vars: true,
         unused: true,
     }
     mangle = {}
@@ -1158,8 +1159,8 @@ replace_all_var_scope: {
         var a = 100, b = 10;
         (function(r, a) {
             switch (~a) {
-            case (b += a):
-            case a++:
+              case (b += a):
+              case a++:
             }
         })(--b, a);
         console.log(a, b);
@@ -1168,8 +1169,8 @@ replace_all_var_scope: {
         var a = 100, b = 10;
         (function(c) {
             switch (~a) {
-            case (b += a):
-            case c++:
+              case (b += a):
+              case +c:
             }
         })((--b, a));
         console.log(a, b);