Correct memory leak in MediaConstraints

brentfulgham · brentfulgham · commit 613d76aff421 · 2017-02-02T19:33:09.000Z
https://bugs.webkit.org/show_bug.cgi?id=167744 <rdar://problem/30331444> Reviewed by Anders Carlsson. ConstraintHolder returns a reference to an object created by operator new. When the returned value is assigned or stored in Vector or other containers we leak memory. Instead, this value should just be returned as a regular object so that the return value optimization can make sure memory is properly (and efficiently) used. * platform/mediastream/MediaConstraints.h: (WebCore::FlattenedConstraint::ConstraintHolder::create): Return by value. Canonical link: https://commits.webkit.org/184789@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@211579 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
@@ -1,3 +1,19 @@
+2017-02-02  Brent Fulgham  <bfulgham@apple.com>
+
+        Correct memory leak in MediaConstraints
+        https://bugs.webkit.org/show_bug.cgi?id=167744
+        <rdar://problem/30331444>
+
+        Reviewed by Anders Carlsson.
+
+        ConstraintHolder returns a reference to an object created by operator new. When the
+        returned value is assigned or stored in Vector or other containers we leak memory.
+        Instead, this value should just be returned as a regular object so that the return
+        value optimization can make sure memory is properly (and efficiently) used.
+
+        * platform/mediastream/MediaConstraints.h:
+        (WebCore::FlattenedConstraint::ConstraintHolder::create): Return by value.
+
 2017-02-02  Andreas Kling  <akling@apple.com>
 
         [Mac] In-process memory pressure monitor for WebContent processes AKA websam
diff --git a/Source/WebCore/platform/mediastream/MediaConstraints.h b/Source/WebCore/platform/mediastream/MediaConstraints.h
@@ -713,7 +713,7 @@ class FlattenedConstraint {
 private:
     class ConstraintHolder {
     public:
-        static ConstraintHolder& create(const MediaConstraint& value) { return *new ConstraintHolder(value); }
+        static ConstraintHolder create(const MediaConstraint& value) { return ConstraintHolder(value); }
 
         ~ConstraintHolder()
         {

Original file line number	Diff line number	Diff line change
`@@ -713,7 +713,7 @@ class FlattenedConstraint {`
`713`	`713`	`private:`
`714`	`714`	`class ConstraintHolder {`
`715`	`715`	`public:`
`716`		`- static ConstraintHolder& create(const MediaConstraint& value) { return *new ConstraintHolder(value); }`
	`716`	`+ static ConstraintHolder create(const MediaConstraint& value) { return ConstraintHolder(value); }`
`717`	`717`
`718`	`718`	`~ConstraintHolder()`
`719`	`719`	`{`