Change SkFileDescriptorStream to handle failure to open the file descriptor

skia/ext/SkFontHost_fontconfig.cpp

 /* libs/graphics/ports/SkFontHost_fontconfig.cpp
 **
 ** Copyright 2008, Google Inc.
 **
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 **
 **     http://www.apache.org/licenses/LICENSE-2.0
 **
@@ skipping 225 matching lines @@
     return 0;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkFileDescriptorStream : public SkStream {
   public:
     SkFileDescriptorStream(int fd) {
         memory_ = NULL;
         offset_ = 0;
+        length_ = 0;

[bungeman-skia, 2011/12/05 21:02:45]

This is following the existing convention, but should these not be set in the
initialization list?

 
         struct stat st;
         if (fstat(fd, &st))
             return;
 
         void* memory = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
         close(fd);
         if (memory == MAP_FAILED)
             return;
 
@@ skipping 10 matching lines @@
         return true;
     }
 
     // SkStream implementation.
     virtual size_t read(void* buffer, size_t size) {
         if (!buffer && !size) {
             // This is request for the length of the stream.
             return length_;
         }
 
-        if (!buffer) {
-            // This is a request to skip bytes.
-            if (offset_ + size < offset_)
-                return offset_;
-            offset_ += size;
-            if (offset_ > length_)
-                offset_ = length_;
-            return offset_;
-        }
-
         size_t remaining = length_ - offset_;
         if (size > remaining)
             size = remaining;
-        memcpy(buffer, memory_ + offset_, size);
+        if (buffer)
+            memcpy(buffer, memory_ + offset_, size);
+
         offset_ += size;
         return size;
     }
 
     virtual const void* getMemoryBase() {
         return memory_;
     }
 
   private:
     const uint8_t* memory_;
@@ skipping 43 matching lines @@
         if (!path)
           return 1;
     }
 
     if (path)
         SkASSERT(!"SkFontHost::GetFileName does not support the font path "
                   "retrieval.");
 
     return 0;
 }