fix corner case in reduce_vars (#5862)

fixes #5860 fixes #5861
mishoo · Jun 20, 2024 · 205a1d1 · 205a1d1
1 parent 95d3ede
commit 205a1d1
Show file tree

Hide file tree

Showing 2 changed files with 143 additions and 2 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -985,7 +985,6 @@ Compressor.prototype.compress = function(node) {
             var scan = ld || left instanceof AST_Destructured;
             switch (node.operator) {
               case "=":
-                if (ld) assign(tw, ld);
                 if (left.equals(right) && !left.has_side_effects(compressor)) {
                     right.walk(tw);
                     walk_prop(left);
@@ -1009,12 +1008,12 @@ Compressor.prototype.compress = function(node) {
               case "||=":
               case "??=":
                 var lazy = true;
-                if (ld) assign(tw, ld);
               default:
                 if (!scan) {
                     mark_assignment_to_arguments(left);
                     return walk_lazy();
                 }
+                assign(tw, ld);
                 ld.assignments++;
                 var fixed = ld.fixed;
                 if (is_modified(compressor, tw, node, node, 0)) {
@@ -1083,6 +1082,7 @@ Compressor.prototype.compress = function(node) {
                         return;
                     }
                     var d = sym.definition();
+                    assign(tw, d);
                     d.assignments++;
                     if (!fixed || sym.in_arg || !safe_to_assign(tw, d)) {
                         walk();
@@ -1613,6 +1613,7 @@ Compressor.prototype.compress = function(node) {
                     return node.value || make_node(AST_Undefined, node);
                 }, function(name, fixed) {
                     var d = name.definition();
+                    assign(tw, d);
                     if (!d.first_decl && d.references.length == 0) d.first_decl = name;
                     if (fixed && safe_to_assign(tw, d, true)) {
                         mark(tw, d);

diff --git a/test/compress/side_effects.js b/test/compress/side_effects.js
@@ -827,3 +827,143 @@ keep_access_after_call: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5860_drop_1: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        var a = {};
+        a.p;
+        var a;
+        a.q;
+        console.log("PASS");
+    }
+    expect: {
+        var a = {};
+        a.p;
+        var a;
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5860_drop_2: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        a = {};
+        a.p;
+        var a;
+        a.q;
+        console.log("PASS");
+    }
+    expect: {
+        a = {};
+        a.p;
+        var a;
+        console.log("PASS");
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5860_keep_1: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        var a = {};
+        a.p;
+        a.q;
+        var a = null;
+        try {
+            a.r;
+            console.log("FAIL");
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        var a = {};
+        a.p;
+        var a = null;
+        try {
+            a.r;
+            console.log("FAIL");
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5860_keep_2: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        a = {};
+        a.p;
+        a.q;
+        var a = null;
+        try {
+            a.r;
+            console.log("FAIL");
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        a = {};
+        a.p;
+        var a = null;
+        try {
+            a.r;
+            console.log("FAIL");
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5860_keep_3: {
+    options = {
+        pure_getters: "strict",
+        reduce_vars: true,
+        side_effects: true,
+    }
+    input: {
+        var a = {};
+        a.p;
+        a.q;
+        a = null;
+        try {
+            a.r;
+            console.log("FAIL");
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect: {
+        var a = {};
+        a.p;
+        a = null;
+        try {
+            a.r;
+            console.log("FAIL");
+        } catch (e) {
+            console.log("PASS");
+        }
+    }
+    expect_stdout: "PASS"
+}