[core] Do not make pending requests for already requested images.

so that processing for the corresponding tile does not suspend and
the rendering performance is not affected.

2 files changed, 9 insertions, 18 deletions

diff --git a/src/mbgl/renderer/image_manager.cpp b/src/mbgl/renderer/image_manager.cpp
index 7b51fb9a2e..108376d190 100644
--- a/src/mbgl/renderer/image_manager.cpp
+++ b/src/mbgl/renderer/image_manager.cpp
@@ -197,16 +197,13 @@ void ImageManager::checkMissingAndNotify(ImageRequestor& requestor, const ImageR
                     existingRequestors.emplace(requestorPtr);
                     continue;
                 }
-                // Unlike icons, pattern changes are not caught
-                // with style-diff meaning that the existing request
-                // could be from the previous style and we cannot
-                // coalesce requests for them.
-                if (dependency.second != ImageType::Pattern) {
-                    continue;
-                }
+                // The request for this image has been already delivered
+                // to the client, so we do not treat it as pending.
+                existingRequestors.emplace(requestorPtr);
+            } else {
+                requestedImages[missingImage].emplace(requestorPtr);
+                requestor.addPendingRequest(missingImage);
             }
-            requestedImages[missingImage].emplace(requestorPtr);
-            requestor.addPendingRequest(missingImage);
 
             auto removePendingRequests = [this, missingImage] {
                 auto existingRequest = requestedImages.find(missingImage);
diff --git a/test/renderer/image_manager.test.cpp b/test/renderer/image_manager.test.cpp
index 20c0a3a7f3..d1d0a83c44 100644
--- a/test/renderer/image_manager.test.cpp
+++ b/test/renderer/image_manager.test.cpp
@@ -187,20 +187,14 @@ TEST(ImageManager, OnStyleImageMissingBeforeSpriteLoaded) {
     EXPECT_EQ(observer.count, 1);
     ASSERT_TRUE(notified);
 
-    // Repeated request of the same image shall not result another
-    // `ImageManagerObserver.onStyleImageMissing()` call.
-    imageManager.getImages(requestor, std::make_pair(dependencies, ++imageCorrelationID));
-    runLoop.runOnce();
-
-    EXPECT_EQ(observer.count, 1);
-
     // Request for updated dependencies must be dispatched to the
     // observer.
     dependencies.emplace("post", ImageType::Icon);
     imageManager.getImages(requestor, std::make_pair(dependencies, ++imageCorrelationID));
-    runLoop.runOnce();
+    ASSERT_TRUE(requestor.hasPendingRequests());
 
-    EXPECT_EQ(observer.count, 2);
+    runLoop.runOnce();
+    ASSERT_FALSE(requestor.hasPendingRequests());
 
     // Another requestor shall not have pending requests for already obtained images.
     StubImageRequestor anotherRequestor(imageManager);