Store null font lookup result into font cache

src/ports/SkFontHost_fontconfig.cpp

Index: src/ports/SkFontHost_fontconfig.cpp
diff --git a/src/ports/SkFontHost_fontconfig.cpp b/src/ports/SkFontHost_fontconfig.cpp
index 1394efdda3c25f77132da87a3d164be028ad1d7e..600b0e5a87ebf0e64ba581df549209300bcc7b16 100644
--- a/src/ports/SkFontHost_fontconfig.cpp
+++ b/src/ports/SkFontHost_fontconfig.cpp
@@ -131,6 +131,11 @@ private:
         SkAutoTUnref<SkTypeface> fFace;
     };
 
+    struct LookUpContext {
+        bool found;
+        SkTypeface* face;
+    };
+
     SkResourceCache fCachedResults;
 
 public:
@@ -141,16 +146,18 @@ public:
         fCachedResults.add(new Result(request, face));
     }
     /** Does not take ownership of request. */
-    SkTypeface* findAndRef(Request* request) {
-        SkTypeface* face = nullptr;
+    bool findAndRef(Request* request, SkTypeface** face) {
+        LookUpContext lookup_context = {false, nullptr};
         fCachedResults.find(*request, [](const SkResourceCache::Rec& rec, void* context) -> bool {
             const Result& result = static_cast<const Result&>(rec);
-            SkTypeface** face = static_cast<SkTypeface**>(context);
+            LookUpContext* lookup_context = static_cast<LookUpContext*>(context);
 
-            *face = result.fFace;
+            lookup_context->found = true;
+            lookup_context->face = result.fFace;
             return true;
-        }, &face);
-        return SkSafeRef(face);
+        }, &lookup_context);
+        *face = SkSafeRef(lookup_context.face);
+        return lookup_context.found;
     }
 
     /** Takes ownership of request. It will be deleted when no longer needed. */
@@ -160,9 +167,9 @@ public:
     }
 
     /** Does not take ownership of request. */
-    static SkTypeface* FindAndRef(Request* request) {
+    static bool FindAndRef(Request* request, SkTypeface** face) {
         SkAutoMutexAcquire ama(gSkFontHostRequestCacheMutex);
-        return Get().findAndRef(request);
+        return Get().findAndRef(request, face);
     }
 };
 
@@ -177,8 +184,8 @@ SkTypeface* FontConfigTypeface::LegacyCreateTypeface(const char requestedFamilyN
     // Check if this request is already in the request cache.
     using Request = SkFontHostRequestCache::Request;
     SkAutoTDelete<Request> request(Request::Create(requestedFamilyName, requestedStyle));
-    SkTypeface* face = SkFontHostRequestCache::FindAndRef(request);
-    if (face) {
+    SkTypeface* face;
+    if (SkFontHostRequestCache::FindAndRef(request, &face)) {
         return face;
     }
 
@@ -188,6 +195,7 @@ SkTypeface* FontConfigTypeface::LegacyCreateTypeface(const char requestedFamilyN
     if (!fci->matchFamilyName(requestedFamilyName, requestedStyle,
                               &identity, &outFamilyName, &outStyle))
     {
+        SkFontHostRequestCache::Add(nullptr, request.release());
         return nullptr;
     }