VertexArrayGL: fix an off by one error for indexRange for drawElements

DrawElements' range was of the form [start, end] while DrawArrays' was of the form [start, end), which caused an out of bound array access in the client vertex pointers. This issue was detected while running angle_end2end_tests with AddressSanitizer. BUG=angleproject:1137 Change-Id: Id9abddf29eaf73bacfd08d1616a999be2fe616b8 Reviewed-on: https://chromium-review.googlesource.com/295122Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Corentin Wallez <cwallez@chromium.org>

VertexArrayGL: fix an off by one error for indexRange for drawElements
2c34a4b0 · Corentin Wallez · 83f3411d · 2c34a4b0 · 2c34a4b0
Commit 2c34a4b0 authored Aug 25, 2015 by Corentin Wallez
Hide whitespace changes
Inline Side-by-side

Showing with 2 additions and 3 deletions

mathutil.h src/common/mathutil.h +0 -1

VertexArrayGL.cpp src/libANGLE/renderer/gl/VertexArrayGL.cpp +2 -2

No files found.
--- a/src/common/mathutil.h
+++ b/src/common/mathutil.h
@@ -503,7 +503,6 @@ inline unsigned int averageFloat10(unsigned int a, unsigned int b)
    return float32ToFloat10((float10ToFloat32(static_cast<unsigned short>(a)) + float10ToFloat32(static_cast<unsigned short>(b))) * 0.5f);
 }
-// Represents intervals of the type [a, b)
 template <typename T>
 struct Range
 {

--- a/src/libANGLE/renderer/gl/VertexArrayGL.cpp
+++ b/src/libANGLE/renderer/gl/VertexArrayGL.cpp
@@ -116,9 +116,9 @@ gl::Error VertexArrayGL::syncDrawState(const gl::AttributesMask &activeAttribute
    }
    else
    {
-        // Not an indexed call, set the range to [first, first + count)
+        // Not an indexed call, set the range to [first, first + count - 1]
        indexRange.start = first;
-        indexRange.end = first + count;
+        indexRange.end = first + count - 1;
    }
    if (attributesNeedStreaming)