commit a883acab4a7686a2c59d0e44024cbe892399dee5
author Chris Dalton <csmartdalton@google.com> Thu Mar 08 23:05:30 2018 -0700
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Mar 09 16:34:11 2018 +0000
tree 19a4f0d8b5086c4da9ccca19e918d003f8a639cf
parent f865b05fe50ca2c094b9c60e4405c6094415b4f6

ccpr: Fix stale array access after dynamic resize

Bug: skia:7656
Change-Id: I0db2219a1c31e966e1da064011c849b4458ff9c1
Reviewed-on: https://skia-review.googlesource.com/113363
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

src/gpu/ccpr/GrCCPathParser.cpp

diff --git a/src/gpu/ccpr/GrCCPathParser.cpp b/src/gpu/ccpr/GrCCPathParser.cpp
index fd0b71d..cb5311f 100644
--- a/src/gpu/ccpr/GrCCPathParser.cpp
+++ b/src/gpu/ccpr/GrCCPathParser.cpp
@@ -262,23 +262,23 @@
 GrCCPathParser::CoverageCountBatchID GrCCPathParser::closeCurrentBatch() {
     SkASSERT(!fInstanceBuffer);
     SkASSERT(!fCoverageCountBatches.empty());
-    const auto& lastBatch = fCoverageCountBatches.back();
-    const auto& lastScissorSubBatch = fScissorSubBatches[lastBatch.fEndScissorSubBatchIdx - 1];
 
+    const auto& lastBatch = fCoverageCountBatches.back();
+    int maxMeshes = 1 + fScissorSubBatches.count() - lastBatch.fEndScissorSubBatchIdx;
+    fMaxMeshesPerDraw = SkTMax(fMaxMeshesPerDraw, maxMeshes);
+
+    const auto& lastScissorSubBatch = fScissorSubBatches[lastBatch.fEndScissorSubBatchIdx - 1];
     PrimitiveTallies batchTotalCounts = fTotalPrimitiveCounts[(int)ScissorMode::kNonScissored] -
                                         lastBatch.fEndNonScissorIndices;
     batchTotalCounts += fTotalPrimitiveCounts[(int)ScissorMode::kScissored] -
                         lastScissorSubBatch.fEndPrimitiveIndices;
 
+    // This will invalidate lastBatch.
     fCoverageCountBatches.push_back() = {
         fTotalPrimitiveCounts[(int)ScissorMode::kNonScissored],
         fScissorSubBatches.count(),
         batchTotalCounts
     };
-
-    int maxMeshes = 1 + fScissorSubBatches.count() - lastBatch.fEndScissorSubBatchIdx;
-    fMaxMeshesPerDraw = SkTMax(fMaxMeshesPerDraw, maxMeshes);
-
     return fCoverageCountBatches.count() - 1;
 }