From 6da7796cbe8a17efd61a3302369e69bb222fdb4f Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@google.com>
Date: Thu, 21 Aug 2014 16:30:03 -0400
Subject: Fix Layout initialization in the skipCache path

C++ local var initialization always tricks me.  Previously, Layout
didn't have a constructor, which meant that defining it on the stack
left mAdvance uninitialized.  This was not an issue when we were doing
"new Layout()", since that invokes zero-initialization, but was an
issue for the skipCache path that was allocating layout on stack by
just "Layout l" instead of "Layout l = Layout()".  To avoid surprises,
add a constructors that clears everything.

Also adds reset() method to reset the layout for reuse.

Change-Id: I3e02f00da9dd7d360abe13f63c310f6882292d0a
---
 libs/minikin/Layout.cpp | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

(limited to 'libs/minikin/Layout.cpp')

diff --git a/libs/minikin/Layout.cpp b/libs/minikin/Layout.cpp
index e355730..46819d6 100644
--- a/libs/minikin/Layout.cpp
+++ b/libs/minikin/Layout.cpp
@@ -267,10 +267,18 @@ void MinikinRect::join(const MinikinRect& r) {
     }
 }
 
-// TODO: the actual initialization is deferred, maybe make this explicit
+// Deprecated. Remove when callers are removed.
 void Layout::init() {
 }
 
+void Layout::reset() {
+    mGlyphs.clear();
+    mFaces.clear();
+    mBounds.setEmpty();
+    mAdvances.clear();
+    mAdvance = 0;
+}
+
 void Layout::setFontCollection(const FontCollection* collection) {
     mCollection = collection;
 }
@@ -519,12 +527,9 @@ void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bu
     bool isRtl = (bidiFlags & kDirection_Mask) != 0;
     bool doSingleRun = true;
 
-    mGlyphs.clear();
-    mFaces.clear();
-    mBounds.setEmpty();
-    mAdvances.clear();
+    reset();
     mAdvances.resize(count, 0);
-    mAdvance = 0;
+
     if (!(bidiFlags == kBidi_Force_LTR || bidiFlags == kBidi_Force_RTL)) {
         UBiDi* bidi = ubidi_open();
         if (bidi) {
-- 
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