Patch taglib to stop loading a FLAC file if it has too many metadata blocks. Fixes issue 3500.

3rdparty/taglib/flac/flacfile.cpp

@@ -416,9 +416,18 @@ void FLAC::File::scan()
   d->blocks.append(new UnknownMetadataBlock(blockType, d->streamInfoData));
   nextBlockOffset += length + 4;
 
+  int blockCount = 0;
+
   // Search through the remaining metadata
   while(!isLastBlock) {
 
+    if (++blockCount > 1024) {
+      debug("FLAC::File::scan() -- FLAC stream has more than 1024 metadata "
+            "blocks, probably corrupt.");
+      setValid(false);
+      return;
+    }
+
     header = readBlock(4);
     blockType = header[0] & 0x7f;
     isLastBlock = (header[0] & 0x80) != 0;

3rdparty/taglib/patches/01-too-many-flac-metadata-blocks.patch

@@ -0,0 +1,29 @@
+commit 0b55f03fa092241dd4533ef0fd4a18b2d97a1b25
+Author: David Sansome <me@davidsansome.com>
+Date:   Sun Feb 17 18:39:49 2013 +1100
+
+    Stop loading a FLAC file if it has too many metadata blocks.
+
+diff --git a/3rdparty/taglib/flac/flacfile.cpp b/3rdparty/taglib/flac/flacfile.cpp
+index a02770a..d308256 100644
+--- a/3rdparty/taglib/flac/flacfile.cpp
++++ b/3rdparty/taglib/flac/flacfile.cpp
+@@ -416,9 +416,18 @@ void FLAC::File::scan()
+   d->blocks.append(new UnknownMetadataBlock(blockType, d->streamInfoData));
+   nextBlockOffset += length + 4;
+ 
++  int blockCount = 0;
++
+   // Search through the remaining metadata
+   while(!isLastBlock) {
+ 
++    if (++blockCount > 1024) {
++      debug("FLAC::File::scan() -- FLAC stream has more than 1024 metadata "
++            "blocks, probably corrupt.");
++      setValid(false);
++      return;
++    }
++
+     header = readBlock(4);
+     blockType = header[0] & 0x7f;
+     isLastBlock = (header[0] & 0x80) != 0;