Preserve hoisted functions after continue. Closes #833

terser · Apr 19, 2023 · 7093b30 · 7093b30
1 parent 374073b
commit 7093b30
Showing 1 changed file with 19 additions and 9 deletions.
diff --git a/lib/compress/tighten-body.js b/lib/compress/tighten-body.js
@@ -1002,27 +1002,34 @@ export function tighten_body(statements, compressor) {
             }
 
             if (stat instanceof AST_If) {
-                var ab = aborts(stat.body);
-                if (can_merge_flow(ab)) {
+                let ab, new_else;
+
+                ab = aborts(stat.body);
+                if (
+                    can_merge_flow(ab)
+                    && (new_else = as_statement_array_with_return(stat.body, ab))
+                ) {
                     if (ab.label) {
                         remove(ab.label.thedef.references, ab);
                     }
                     CHANGED = true;
                     stat = stat.clone();
                     stat.condition = stat.condition.negate(compressor);
-                    var body = as_statement_array_with_return(stat.body, ab);
                     stat.body = make_node(AST_BlockStatement, stat, {
                         body: as_statement_array(stat.alternative).concat(extract_functions())
                     });
                     stat.alternative = make_node(AST_BlockStatement, stat, {
-                        body: body
+                        body: new_else
                     });
                     statements[i] = stat.transform(compressor);
                     continue;
                 }
 
-                var ab = aborts(stat.alternative);
-                if (can_merge_flow(ab)) {
+                ab = aborts(stat.alternative);
+                if (
+                    can_merge_flow(ab)
+                    && (new_else = as_statement_array_with_return(stat.alternative, ab))
+                ) {
                     if (ab.label) {
                         remove(ab.label.thedef.references, ab);
                     }
@@ -1031,9 +1038,8 @@ export function tighten_body(statements, compressor) {
                     stat.body = make_node(AST_BlockStatement, stat.body, {
                         body: as_statement_array(stat.body).concat(extract_functions())
                     });
-                    var body = as_statement_array_with_return(stat.alternative, ab);
                     stat.alternative = make_node(AST_BlockStatement, stat.alternative, {
-                        body: body
+                        body: new_else
                     });
                     statements[i] = stat.transform(compressor);
                     continue;
@@ -1148,7 +1154,11 @@ export function tighten_body(statements, compressor) {
         }
 
         function as_statement_array_with_return(node, ab) {
-            var body = as_statement_array(node).slice(0, -1);
+            var body = as_statement_array(node);
+            if (ab !== body[body.length - 1]) {
+                return undefined;
+            }
+            body = body.slice(0, -1);
             if (ab.value) {
                 body.push(make_node(AST_SimpleStatement, ab.value, {
                     body: ab.value.expression