enhance `conditionals` (#3557)

1 files changed, 10 insertions, 8 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 9e2b6895..a6f5d20b 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -4665,11 +4665,6 @@ merge(Compressor.prototype, {
             self.body = self.alternative || make_node(AST_EmptyStatement, self);
             self.alternative = tmp;
         }
-        if (is_empty(self.body) && is_empty(self.alternative)) {
-            return make_node(AST_SimpleStatement, self.condition, {
-                body: self.condition.clone()
-            }).optimize(compressor);
-        }
         if (self.body instanceof AST_SimpleStatement
             && self.alternative instanceof AST_SimpleStatement) {
             return make_node(AST_SimpleStatement, self, {
@@ -4703,15 +4698,22 @@ merge(Compressor.prototype, {
                 }).transform(compressor)
             }).optimize(compressor);
         }
-        if (self.body instanceof AST_EmptyStatement
-            && self.alternative instanceof AST_SimpleStatement) {
-            return make_node(AST_SimpleStatement, self, {
+        if (is_empty(self.body)) {
+            if (is_empty(self.alternative)) return make_node(AST_SimpleStatement, self.condition, {
+                body: self.condition.clone()
+            }).optimize(compressor);
+            if (self.alternative instanceof AST_SimpleStatement) return make_node(AST_SimpleStatement, self, {
                 body: make_node(AST_Binary, self, {
                     operator : "||",
                     left     : self.condition,
                     right    : self.alternative.body
                 }).transform(compressor)
             }).optimize(compressor);
+            self = make_node(AST_If, self, {
+                condition: negated,
+                body: self.alternative,
+                alternative: null
+            });
         }
         if (self.body instanceof AST_Exit
             && self.alternative instanceof AST_Exit