From: Tsuda Kageyu <tsuda.kageyu@gmail.com>
Date: Wed, 29 Jul 2015 11:52:56 +0000 (+0900)
Subject: Make FLAC::File tolerant to zero-sized padding blocks.
X-Git-Tag: v1.10beta~63^2~1
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6f944b02918c61528b977442c64c9b4bfd50078a;p=taglib

Make FLAC::File tolerant to zero-sized padding blocks.
---

diff --git a/taglib/flac/flacfile.cpp b/taglib/flac/flacfile.cpp
index 823170aa..6df8f6b9 100644
--- a/taglib/flac/flacfile.cpp
+++ b/taglib/flac/flacfile.cpp
@@ -421,9 +421,15 @@ void FLAC::File::scan()
     isLastBlock = (header[0] & 0x80) != 0;
     length = header.toUInt(1U, 3U);
 
-    ByteVector data = readBlock(length);
-    if(data.size() != length || length == 0) {
-      debug("FLAC::File::scan() -- FLAC stream corrupted");
+    if(length == 0 && blockType != MetadataBlock::Padding) {
+      debug("FLAC::File::scan() -- Zero-sized metadaba block found");
+      setValid(false);
+      return;
+    }
+
+    const ByteVector data = readBlock(length);
+    if(data.size() != length) {
+      debug("FLAC::File::scan() -- Failed to read a metadata block");
       setValid(false);
       return;
     }
@@ -446,7 +452,7 @@ void FLAC::File::scan()
         block = picture;
       }
       else {
-        debug("FLAC::File::scan() -- invalid picture found, discarting");
+        debug("FLAC::File::scan() -- invalid picture found, discarding");
         delete picture;
       }
     }
diff --git a/tests/data/zero-sized-padding.flac b/tests/data/zero-sized-padding.flac
new file mode 100644
index 00000000..86ab8bf7
Binary files /dev/null and b/tests/data/zero-sized-padding.flac differ
diff --git a/tests/test_flac.cpp b/tests/test_flac.cpp
index f99a679a..164020a6 100644
--- a/tests/test_flac.cpp
+++ b/tests/test_flac.cpp
@@ -25,6 +25,7 @@ class TestFLAC : public CppUnit::TestFixture
   CPPUNIT_TEST(testSaveMultipleValues);
   CPPUNIT_TEST(testDict);
   CPPUNIT_TEST(testInvalid);
+  CPPUNIT_TEST(testZeroSizedPadding);
   CPPUNIT_TEST_SUITE_END();
 
 public:
@@ -255,6 +256,14 @@ public:
     CPPUNIT_ASSERT_EQUAL(TagLib::uint(0), f.properties().size());
   }
 
+  void testZeroSizedPadding()
+  {
+    ScopedFileCopy copy("zero-sized-padding", ".flac");
+
+    FLAC::File f(copy.fileName().c_str());
+    CPPUNIT_ASSERT(f.isValid());
+  }
+
 };
 
 CPPUNIT_TEST_SUITE_REGISTRATION(TestFLAC);