fix($parse): Handle sign of -undefined consistently

lgalfaso · lgalfaso · commit c1eaf3480b9a · 2016-04-18T16:29:10.000+02:00
When csp is disabled, evaluating `-undefined` is `-0` and when csp is enabled the evaluation is `0`. In most cases this is not an issue as `0 === -0`, but there is an edge case as `1/0 === Infinity` and `1/-0 === -Infinity` Close: angular#14451
diff --git a/src/ng/parse.js b/src/ng/parse.js
@@ -1516,7 +1516,7 @@ ASTInterpreter.prototype = {
       if (isDefined(arg)) {
         arg = -arg;
       } else {
-        arg = 0;
+        arg = -0;
       }
       return context ? {value: arg} : arg;
     };
diff --git a/test/ng/parseSpec.js b/test/ng/parseSpec.js
@@ -1755,7 +1755,7 @@ describe('parser', function() {
         expect(scope.$eval("+'1'")).toEqual(+'1');
         expect(scope.$eval("-'1'")).toEqual(-'1');
         expect(scope.$eval("+undefined")).toEqual(0);
-        expect(scope.$eval("-undefined")).toBe(0);
+        expect(scope.$eval("-undefined")).toEqual(-0);
         expect(scope.$eval("+null")).toEqual(+null);
         expect(scope.$eval("-null")).toEqual(-null);
         expect(scope.$eval("+false")).toEqual(+false);

Original file line number	Diff line number	Diff line change
`@@ -1516,7 +1516,7 @@ ASTInterpreter.prototype = {`
`1516`	`1516`	`if (isDefined(arg)) {`
`1517`	`1517`	`arg = -arg;`
`1518`	`1518`	`} else {`
`1519`		`- arg = 0;`
	`1519`	`+ arg = -0;`
`1520`	`1520`	`}`
`1521`	`1521`	`return context ? {value: arg} : arg;`
`1522`	`1522`	`};`