Fix memory leak when sinks throw an exception

nemequ · nemequ · commit 36f9f04a0080 · 2015-09-27T16:42:41.000-07:00
This allows custom sink implementations which can throw an exception
(for example, when there is insufficient space to store the output)
to be used, while avoiding memory leaks which could occur in the event
such an exception is thrown.
diff --git a/gipfeli-internal.cc b/gipfeli-internal.cc
@@ -268,7 +268,13 @@ size_t Gipfeli::CompressStream(
     }
 
     if (scratch_output == dest) {
-      writer->AppendMemBlock(new NewedMemBlock(scratch_output, output_size));
+      NewedMemBlock* new_block = new NewedMemBlock(scratch_output, output_size);
+      try {
+        writer->AppendMemBlock(new_block);
+      } catch (...) {
+        delete new_block;
+        throw;
+      }
       scratch_output = NULL;
       scratch_output_size = 0;
     } else {
