fix corner cases in unsafe_math (#3532)

fixes #3531
mishoo · Oct 27, 2019 · a270ba6 · a270ba6
1 parent 37f35e4
commit a270ba6
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Showing 2 changed files with 259 additions and 73 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -5930,7 +5930,8 @@ merge(Compressor.prototype, {
                 // a - -b => a + b
                 if (self.right instanceof AST_UnaryPrefix
                     && self.right.operator == "-"
-                    && self.left.is_number(compressor)) {
+                    && self.left.is_number(compressor)
+                    && self.right.expression.is_number(compressor)) {
                     self = make_node(AST_Binary, self, {
                         operator: "+",
                         left: self.left,
@@ -5979,6 +5980,7 @@ merge(Compressor.prototype, {
                 // a + (b + c) => (a + b) + c
                 if (self.right instanceof AST_Binary
                     && self.right.operator != "%"
+                    && self.right.is_number(compressor)
                     && PRECEDENCE[self.right.operator] == PRECEDENCE[self.operator]) {
                     self = make_node(AST_Binary, self, {
                         operator: align(self.operator, self.right.operator),
@@ -5991,14 +5993,23 @@ merge(Compressor.prototype, {
                         }),
                         right: self.right.right
                     });
+                    if (self.operator == "+"
+                        && !self.right.is_boolean(compressor)
+                        && !self.right.is_number(compressor)) {
+                        self.right = make_node(AST_UnaryPrefix, self.right, {
+                            operator: "+",
+                            expression: self.right
+                        });
+                    }
                 }
                 // (2 * n) * 3 => 6 * n
                 // (n + 2) + 3 => n + 5
                 if (self.right instanceof AST_Constant
                     && self.left instanceof AST_Binary
                     && self.left.operator != "%"
                     && PRECEDENCE[self.left.operator] == PRECEDENCE[self.operator]) {
-                    if (self.left.left instanceof AST_Constant) {
+                    if (self.left.left instanceof AST_Constant
+                        && (self.left.operator != "+" || self.left.right.is_number(compressor))) {
                         self = make_node(AST_Binary, self, {
                             operator: self.left.operator,
                             left: make_node(AST_Binary, self.left, {
@@ -6010,7 +6021,8 @@ merge(Compressor.prototype, {
                             }),
                             right: self.left.right
                         });
-                    } else if (self.left.right instanceof AST_Constant) {
+                    } else if (self.left.right instanceof AST_Constant
+                        && (self.left.operator != "+" || self.left.left.is_number(compressor))) {
                         self = make_node(AST_Binary, self, {
                             operator: self.left.operator,
                             left: self.left.left,