From 032a35954c6ceb9ab76c728c7638408e0fc07972 Mon Sep 17 00:00:00 2001
From: Raph Levien <raph@google.com>
Date: Thu, 14 Apr 2016 21:22:37 -0700
Subject: [PATCH] Don't do layout in hasGlyph for codepoint + vs

In the case where the input is a base codepoint + a variation selector,
the code currently checks hasVariationSelector and then does a layout,
checking for a single glyph. However, HarfBuzz in some cases will change
the VS into a space glyph, so hasGlyph will return false.

This patch makes hasGlyph rely entirely on the hasVariationSelector
method in the case of a base codepoint + a VS

Bug: 27531970
Bug: 28182689
Change-Id: Id190c427149213509f2d779ec1aa330feb4b62d8
---
 core/jni/android/graphics/Paint.cpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/core/jni/android/graphics/Paint.cpp b/core/jni/android/graphics/Paint.cpp
index f46f45cc5e5d5..898cf77cb32dc 100644
--- a/core/jni/android/graphics/Paint.cpp
+++ b/core/jni/android/graphics/Paint.cpp
@@ -815,10 +815,15 @@ namespace PaintGlue {
             }
 
             if (prevCp != kStartOfString &&
-                ((0xFE00 <= cp && cp <= 0xFE0F) || (0xE0100 <= cp && cp <= 0xE01EF)) &&
-                !MinikinUtils::hasVariationSelector(typeface, prevCp, cp)) {
-                // No font has a glyph for the code point and variation selector pair.
-                return false;
+                ((0xFE00 <= cp && cp <= 0xFE0F) || (0xE0100 <= cp && cp <= 0xE01EF))) {
+                bool hasVS = MinikinUtils::hasVariationSelector(typeface, prevCp, cp);
+                if (!hasVS) {
+                    // No font has a glyph for the code point and variation selector pair.
+                    return false;
+                } else if (nChars == 1 && i + 1 == str.size()) {
+                    // The string is just a codepoint and a VS, we have an authoritative answer
+                    return true;
+                }
             }
             nChars++;
             prevCp = cp;