fixed GH #2661: Poco::Zip::ZipArchive cannot load new tomcat.zip file

Zip/doc/ZipUserGuide.page

@@ -11,7 +11,7 @@ POCO Zip adds support for parsing and creating Zip files. It offers the followin
 !!Restrictions
   * POCO Zip does not support the DEFLATE64 algorithm.
   * encrypted files are not supported
-  
+
 !!!Main Classes
 Most users will work with two common classes: <*Compress*> and <*Decompress*>
 
@@ -23,31 +23,31 @@ Creating a Zip file is a basically a three-step process:
      Compress(std::ostream& out, bool seekableOut);
 ----
   * Add entries: either add single files or directory entries
-  
-    void addFile(std::istream& input, 
-                 const Poco::DateTime& lastModifiedAt, 
-                 const Poco::Path& fileName, 
-                 ZipCommon::CompressionMethod cm = ZipCommon::CM_DEFLATE, 
+
+    void addFile(std::istream& input,
+                 const Poco::DateTime& lastModifiedAt,
+                 const Poco::Path& fileName,
+                 ZipCommon::CompressionMethod cm = ZipCommon::CM_DEFLATE,
                  ZipCommon::CompressionLevel cl = ZipCommon::CL_MAXIMUM);
         /// Adds a single file to the Zip File. fileName must not be a directory name.
 
-    void addFile(const Poco::Path& file, 
-                 const Poco::Path& fileName, 
-                 ZipCommon::CompressionMethod cm = ZipCommon::CM_DEFLATE, 
+    void addFile(const Poco::Path& file,
+                 const Poco::Path& fileName,
+                 ZipCommon::CompressionMethod cm = ZipCommon::CM_DEFLATE,
                  ZipCommon::CompressionLevel cl = ZipCommon::CL_MAXIMUM);
         /// Adds a single file to the Zip File. fileName must not be a directory name. The file must exist physically!
 
     void addDirectory(const Poco::Path& entryName, const Poco::DateTime& lastModifiedAt);
         /// Adds a directory entry excluding all children to the Zip file, entryName must not be empty.
 
-    void addRecursive(const Poco::Path& entry, 
-                      ZipCommon::CompressionLevel cl = ZipCommon::CL_MAXIMUM, 
-                      bool excludeRoot = true, 
+    void addRecursive(const Poco::Path& entry,
+                      ZipCommon::CompressionLevel cl = ZipCommon::CL_MAXIMUM,
+                      bool excludeRoot = true,
                       const Poco::Path& name = Poco::Path());
         /// Adds a directory entry recursively to the zip file, set excludeRoot to false to exclude the parent directory.
         /// The name specifies under which path the entries are added in the Zip file.
 ----
-Note that one must always define a name when adding a file entry, otherwise the compresser can not decide if the file should be added with an absolute or a relative path. 
+Note that one must always define a name when adding a file entry, otherwise the compresser can not decide if the file should be added with an absolute or a relative path.
 Assume you are adding the file <*c:\\data\\hello.txt*> twice to a Zip:
 
     // MUST use binary!
@@ -96,7 +96,7 @@ To get notified about the entries that are added during <*addRecursive*> registe
     Poco::FIFOEvent<const ZipLocalFileHeader> EDone;
 ----
   * Closing the Zip file: It is mandatory to manually close Compress objects. This guarantees that the Zip directory is written, thus creating a valid Zip file. It is safe to call <*close*> multiple times, only the first call takes effect.
-  
+
     ZipArchive close();
 ----
 <*close*> returns a ZipArchive which describes all entries inside a Zip file.
@@ -110,7 +110,7 @@ The following sample code shows how all entries can be extracted from a Zip file
     std::ifstream inp("test.zip", std::ios::binary);
     poco_assert (inp);
     // decompress to current working dir
-    Decompress dec(inp, Poco::Path()); 
+    Decompress dec(inp, Poco::Path());
     // if an error happens invoke the ZipTest::onDecompressError method
     dec.EError += Poco::Delegate<ZipTest, std::pair<const Poco::Zip::ZipLocalFileHeader, const std::string> >(this, &ZipTest::onDecompressError);
     dec.decompressAllFiles();
@@ -152,7 +152,8 @@ To decompress single files you must first parse a Zip file, and then decompress
     ZipArchive arch(inp);
     ZipArchive::FileHeaders::const_iterator it = arch.findHeader("data/hello.txt");
     poco_assert (it != arch.headerEnd());
-    ZipInputStream zipin (inp, it->second);
+    inp.clear();
+    ZipInputStream zipin(inp, it->second);
     std::ostringstream out(std::ios::binary);
     Poco::StreamCopier::copyStream(zipin, out);
 ----

Zip/include/Poco/Zip/ZipUtil.h

@@ -54,6 +54,9 @@ public:
 	static void sync(std::istream& in);
 		/// Searches the next valid header in the input stream, stops right before it
 
+	static void syncDataDescriptor(std::istream& in, bool force64);
+		/// Searches the next data descriptor
+
 	static void verifyZipEntryFileName(const std::string& zipPath);
 		/// Verifies that the name of the ZipEntry is a valid path
 

Zip/src/SkipCallback.cpp

@@ -37,7 +37,7 @@ bool SkipCallback::handleZipEntry(std::istream& zipStream, const ZipLocalFileHea
 	if (!hdr.searchCRCAndSizesAfterData())
 		zipStream.seekg(hdr.getCompressedSize(), std::ios_base::cur);
 	else
-		ZipUtil::sync(zipStream);
+		ZipUtil::syncDataDescriptor(zipStream, hdr.needsZip64());
 	if (!zipStream.good()) throw Poco::IOException("Failed to seek on input stream");
 	return true;
 }

Zip/src/ZipFileInfo.cpp

@@ -52,7 +52,7 @@ ZipFileInfo::ZipFileInfo(const ZipLocalFileHeader& header):
 	if (getHostSystem() == ZipCommon::HS_UNIX)
 		setUnixAttributes();
 
-	_rawInfo[GENERAL_PURPOSE_POS+1] |= 0x08; // Set "language encoding flag" to indicate that filenames and paths are in UTF-8.	   
+	_rawInfo[GENERAL_PURPOSE_POS+1] |= 0x08; // Set "language encoding flag" to indicate that filenames and paths are in UTF-8.
 
 	if (header.searchCRCAndSizesAfterData())
 		_rawInfo[GENERAL_PURPOSE_POS] |= 0x08;
@@ -126,8 +126,7 @@ void ZipFileInfo::parse(std::istream& inp, bool assumeHeaderRead)
 				ptr += 2;
 				if (id == ZipCommon::ZIP64_EXTRA_ID)
 				{
-					poco_assert(size >= 8);
-					if (getUncompressedSizeFromHeader() == ZipCommon::ZIP64_MAGIC)
+					if (size >= 8 && getUncompressedSizeFromHeader() == ZipCommon::ZIP64_MAGIC)
 					{
 						setUncompressedSize(ZipUtil::get64BitValue(ptr, 0));
 						size -= 8;

Zip/src/ZipUtil.cpp

@@ -161,6 +161,70 @@ void ZipUtil::sync(std::istream& in)
 }
 
 
+void ZipUtil::syncDataDescriptor(std::istream & in, bool force64)
+{
+	std::streampos start = in.tellg();
+	const int eof = std::char_traits<char>::eof();
+
+	int c = in.get();
+	do
+	{
+		while (c != eof && c != ZipDataInfo::HEADER[0]) { c = in.get(); }
+
+		if (c == eof) return;
+
+		bool match = true;
+		for (int i = 1; i < 4 && match; i++)
+		{
+			c = in.get();
+			if (c != ZipDataInfo::HEADER[i]) match = false;
+		}
+
+		if (match)
+		{
+			std::streampos end = in.tellg();
+
+			if (force64)
+			{
+				ZipDataInfo64 nfo(in, true);
+				if (nfo.isValid())
+				{
+					if (end - start == nfo.getCompressedSize() + 4)
+					{
+						in.seekg(-static_cast<int>(ZipDataInfo64::getFullHeaderSize()), std::ios::cur);
+						if (!in.good()) throw Poco::IOException("Failed to seek on input stream");
+						break;
+					}
+					else
+					{
+						in.seekg(-static_cast<int>(ZipDataInfo64::getFullHeaderSize()) + 4, std::ios::cur);
+						if (!in.good()) throw Poco::IOException("Failed to seek on input stream");
+					}
+				}
+			}
+			else
+			{
+				ZipDataInfo nfo(in, true);
+				if (nfo.isValid())
+				{
+					if (end - start == nfo.getCompressedSize() + 4)
+					{
+						in.seekg(-static_cast<int>(ZipDataInfo::getFullHeaderSize()), std::ios::cur);
+						if (!in.good()) throw Poco::IOException("Failed to seek on input stream");
+						break;
+					}
+					else
+					{
+						in.seekg(-static_cast<int>(ZipDataInfo::getFullHeaderSize()) + 4, std::ios::cur);
+						if (!in.good()) throw Poco::IOException("Failed to seek on input stream");
+					}
+				}
+			}
+		}
+	} while (c != eof);
+}
+
+
 void ZipUtil::verifyZipEntryFileName(const std::string& fn)
 {
 	if (fn.find("\\") != std::string::npos)