fonts: Ignore re-initialization of fallback glyphs from the server.

If the client finds that the server re-initializes a cached path/image,
we consider this an error and invalid data. But since we might
initialize a glyph using a fallback on the client, and receive the
correct version from the server later, this is not longer true.

Bug: 829622
Change-Id: I34ab17b54139d89a15179265d4aed4a1fe36fd47
Reviewed-on: https://skia-review.googlesource.com/133566
Commit-Queue: Khusal Sagar <khushalsagar@chromium.org>
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>

1 files changed, 20 insertions, 11 deletions

diff --git a/src/core/SkRemoteGlyphCache.cpp b/src/core/SkRemoteGlyphCache.cpp
index 0ccbf2f15e..fa4767069f 100644
--- a/src/core/SkRemoteGlyphCache.cpp
+++ b/src/core/SkRemoteGlyphCache.cpp
@@ -668,6 +668,8 @@ void SkStrikeServer::SkGlyphCacheState::writePendingGlyphs(Serializer* serialize
         SkGlyph stationaryGlyph = *glyph;
         stationaryGlyph.fImage = serializer->allocate(imageSize, stationaryGlyph.formatAlignment());
         fContext->getImage(stationaryGlyph);
+        // TODO: Generating the image can change the mask format, do we need to update it in the
+        // serialized glyph?
     }
     fPendingGlyphImages.clear();
 
@@ -811,10 +813,14 @@ bool SkStrikeClient::readStrikeData(const volatile void* memory, size_t memorySi
             if (!deserializer.read<SkGlyph>(&glyph)) READ_FAILURE
 
             SkGlyph* allocatedGlyph = strike->getRawGlyphByID(glyph.getPackedID());
-            // Don't override the path, if the glyph has one.
-            auto* glyphPath = allocatedGlyph->fPathData;
-            *allocatedGlyph = glyph;
-            allocatedGlyph->fPathData = glyphPath;
+
+            // Update the glyph unless it's already got an image (from fallback),
+            // preserving any path that might be present.
+            if (allocatedGlyph->fImage == nullptr) {
+                auto* glyphPath = allocatedGlyph->fPathData;
+                *allocatedGlyph = glyph;
+                allocatedGlyph->fPathData = glyphPath;
+            }
 
             bool tooLargeForAtlas = false;
 #if SK_SUPPORT_GPU
@@ -828,9 +834,8 @@ bool SkStrikeClient::readStrikeData(const volatile void* memory, size_t memorySi
             if (imageSize == 0u) continue;
 
             auto* image = deserializer.read(imageSize, allocatedGlyph->formatAlignment());
-            if (!image ||
-                !strike->initializeImage(image, imageSize, allocatedGlyph))
-                READ_FAILURE
+            if (!image) READ_FAILURE
+            strike->initializeImage(image, imageSize, allocatedGlyph);
         }
 
         size_t glyphPathsCount = 0u;
@@ -840,10 +845,14 @@ bool SkStrikeClient::readStrikeData(const volatile void* memory, size_t memorySi
             if (!deserializer.read<SkGlyph>(&glyph)) READ_FAILURE
 
             SkGlyph* allocatedGlyph = strike->getRawGlyphByID(glyph.getPackedID());
-            // Don't override the image, if the glyph has one.
-            auto* glyphImage = allocatedGlyph->fImage;
-            *allocatedGlyph = glyph;
-            allocatedGlyph->fImage = glyphImage;
+
+            // Update the glyph unless it's already got a path (from fallback),
+            // preserving any image that might be present.
+            if (allocatedGlyph->fPathData == nullptr) {
+                auto* glyphImage = allocatedGlyph->fImage;
+                *allocatedGlyph = glyph;
+                allocatedGlyph->fImage = glyphImage;
+            }
 
             if (!read_path(&deserializer, allocatedGlyph, strike.get())) READ_FAILURE
         }