From 6f944b02918c61528b977442c64c9b4bfd50078a Mon Sep 17 00:00:00 2001
From: Tsuda Kageyu <tsuda.kageyu@gmail.com>
Date: Wed, 29 Jul 2015 20:52:56 +0900
Subject: [PATCH] Make FLAC::File tolerant to zero-sized padding blocks.

---
 taglib/flac/flacfile.cpp           |  14 ++++++++++----
 tests/data/zero-sized-padding.flac | Bin 0 -> 4692 bytes
 tests/test_flac.cpp                |   9 +++++++++
 3 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 tests/data/zero-sized-padding.flac

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 0000000000000000000000000000000000000000..86ab8bf7b354855713a5352887c4791dbe2310b0
GIT binary patch
literal 4692
zcmeI$&nv@m9LMp`Y<_HvubCO<*R}(bkn*EQCW~4jJIwN<(I(Bo33E^jDct?I;pCvW
zNg9QNmfWP=+>`?nJDKmRm;b`&U7tQZ`g~5$<2&pPb_*fwCSg*qTp<+0wfjw^Ene=O
zbbW_kR(7wRl!kpn`@Bvl)#?|aQIAa#!q?~X_H_8=$O5u}EFcTW0<wTCAPdL>vVbfg
z3&;Ypz&|YzQ+EWZ<gislurW}V3hR(&hFVKOX(1{eg0vG<jRNWBsk=caeU=J1p^PXs
z8HX~LsLuqHHAL06L3$r`?u87a)anD29iU7HP)<Mf^$Zz%so)lr+eP_}P@adnUx1WS
zYU&lrw^469kg1Tm)j|bWuc$LN2bnXevli&@qo{L37Cqn0k5G}ilEEw=K~@JfG7c3x
zse}tEsiQuQp;8wWx`Aw+RBQz*Yo#pjP<bO&AAu^Gsnc?(a)bKuKvkR6bQ5G>r3MaD
N$*9$#yV$1vJ-_48A29#`

literal 0
HcmV?d00001

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);
-- 
2.40.0