From 12a884e1228378de89913d3ffcf603f6d24a6eb7 Mon Sep 17 00:00:00 2001
From: Scott Wheeler <wheeler@kde.org>
Date: Tue, 12 Feb 2008 03:20:30 +0000
Subject: [PATCH] Messed with things until the algorithm is correct.  rfind now
 passes all unit tests.

git-svn-id: svn://anonsvn.kde.org/home/kde/trunk/kdesupport/taglib@773913 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
---
 taglib/ape/apetag.cpp          |  2 +-
 taglib/mpeg/mpegfile.cpp       | 13 ++++++-------
 taglib/toolkit/tbytevector.cpp | 16 ++++++++++------
 tests/test_bytevector.cpp      |  4 ++--
 4 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/taglib/ape/apetag.cpp b/taglib/ape/apetag.cpp
index e6703ed4..2d628f92 100644
--- a/taglib/ape/apetag.cpp
+++ b/taglib/ape/apetag.cpp
@@ -244,7 +244,7 @@ ByteVector APE::Tag::render() const
   }
 
   d->footer.setItemCount(itemCount);
-  d->footer.setTagSize(data.size()+Footer::size());
+  d->footer.setTagSize(data.size() + Footer::size());
   d->footer.setHeaderPresent(true);
 
   return d->footer.renderHeader() + data + d->footer.renderFooter();
diff --git a/taglib/mpeg/mpegfile.cpp b/taglib/mpeg/mpegfile.cpp
index 704a5fba..f69fd20f 100644
--- a/taglib/mpeg/mpegfile.cpp
+++ b/taglib/mpeg/mpegfile.cpp
@@ -212,7 +212,8 @@ bool MPEG::File::save(int tags, bool stripOthers)
     if(d->hasAPE)
       insert(APETag()->render(), d->APELocation, d->APEOriginalSize);
     else {
-      if(d->hasID3v1)  {
+      if(d->hasID3v1) {
+        debug("inserting ape tag before id3v1 tag");
         insert(APETag()->render(), d->ID3v1Location, 0);
         d->APEOriginalSize = APETag()->footer()->completeTagSize();
         d->hasAPE = true;
@@ -561,15 +562,13 @@ long MPEG::File::findID3v1()
 long MPEG::File::findAPE()
 {
   if(isValid()) {
-    if (d->hasID3v1)
-        seek(-160, End);
-    else
-        seek(-32, End);
-
+    seek(d->hasID3v1 ? -160 : -32, End);
     long p = tell();
 
-    if(readBlock(8) == APE::Tag::fileIdentifier())
+    if(readBlock(8) == APE::Tag::fileIdentifier()) {
+      debug("found ape at " + String::number(int(p)));
       return p;
+    }
   }
   return -1;
 }
diff --git a/taglib/toolkit/tbytevector.cpp b/taglib/toolkit/tbytevector.cpp
index e180e908..59da5192 100644
--- a/taglib/toolkit/tbytevector.cpp
+++ b/taglib/toolkit/tbytevector.cpp
@@ -89,7 +89,7 @@ namespace TagLib {
   };
 
   /*!
-   * A templatized find that works both with a ByteVector and a ByteVectorMirror.
+   * A templatized KMP find that works both with a ByteVector and a ByteVectorMirror.
    */
 
   template <class Vector>
@@ -146,6 +146,7 @@ namespace TagLib {
   {
   public:
     ByteVectorMirror(const ByteVector &source) : v(source) {}
+
     const char operator[](int index) const
     {
       return v[v.size() - index - 1];
@@ -170,6 +171,12 @@ namespace TagLib {
     {
       ByteVectorMirror v(*this);
 
+      if(offset > 0) {
+        offset = size() - offset - pattern.size();
+        if(offset >= size())
+          offset = 0;
+      }
+
       const int pos = vectorFind<ByteVectorMirror>(v, pattern, offset, byteAlign);
 
       // If the offset is zero then we need to adjust the location in the search
@@ -184,14 +191,11 @@ namespace TagLib {
       if(pos == -1)
         return -1;
 
-      if(offset == 0)
-        return size() - pos - pattern.size();
-      else
-        return pos - offset;
+      return size() - pos - pattern.size();
     }
 
   private:
-    const ByteVector v;
+    const ByteVector &v;
   };
 
   template <class T>
diff --git a/tests/test_bytevector.cpp b/tests/test_bytevector.cpp
index 0a343e31..f92fce01 100644
--- a/tests/test_bytevector.cpp
+++ b/tests/test_bytevector.cpp
@@ -139,7 +139,7 @@ public:
 
   void testRfind1()
   {
-    CPPUNIT_ASSERT_EQUAL(-1, ByteVector(".OggS....").rfind("OggS", 0));
+    CPPUNIT_ASSERT_EQUAL(1, ByteVector(".OggS....").rfind("OggS", 0));
     CPPUNIT_ASSERT_EQUAL(1, ByteVector(".OggS....").rfind("OggS", 1));
     CPPUNIT_ASSERT_EQUAL(1, ByteVector(".OggS....").rfind("OggS", 2));
     CPPUNIT_ASSERT_EQUAL(1, ByteVector(".OggS....").rfind("OggS", 3));
@@ -168,7 +168,7 @@ public:
     CPPUNIT_ASSERT_EQUAL(0, r3.find("OggS"));
     CPPUNIT_ASSERT_EQUAL(10, r3.rfind("OggS"));
     CPPUNIT_ASSERT_EQUAL(10, r4.rfind("OggS"));
-    CPPUNIT_ASSERT_EQUAL(0, r4.rfind("OggS", 0));
+    CPPUNIT_ASSERT_EQUAL(10, r4.rfind("OggS", 0));
     CPPUNIT_ASSERT_EQUAL(5, r4.rfind("OggS", 7));
     CPPUNIT_ASSERT_EQUAL(10, r4.rfind("OggS", 12));
   }