Merge pull request #19 from jparishy/master

Fix for Issue #16. Closes #16

Tests/SSZipArchive.xcodeproj/project.pbxproj

@@ -18,6 +18,7 @@
 		B215FB6B143AD576003AC546 /* zip.c in Sources */ = {isa = PBXBuildFile; fileRef = B215FB55143AD460003AC546 /* zip.c */; };
 		B215FB6D143AD6FF003AC546 /* TestArchive.zip in Resources */ = {isa = PBXBuildFile; fileRef = B215FB6C143AD6FF003AC546 /* TestArchive.zip */; };
 		B23FCC7F1558F1B70026375C /* TestPasswordArchive.zip in Resources */ = {isa = PBXBuildFile; fileRef = B23FCC7E1558F1B70026375C /* TestPasswordArchive.zip */; };
+		C5AE4E64155A12760045F3ED /* IncorrectHeaders.zip in Resources */ = {isa = PBXBuildFile; fileRef = C5AE4E63155A12760045F3ED /* IncorrectHeaders.zip */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -40,6 +41,7 @@
 		B215FB64143AD527003AC546 /* libz.dylib */ = {isa = PBXFileReference; lastKnownFileType = "compiled.mach-o.dylib"; name = libz.dylib; path = usr/lib/libz.dylib; sourceTree = SDKROOT; };
 		B215FB6C143AD6FF003AC546 /* TestArchive.zip */ = {isa = PBXFileReference; lastKnownFileType = archive.zip; path = TestArchive.zip; sourceTree = "<group>"; };
 		B23FCC7E1558F1B70026375C /* TestPasswordArchive.zip */ = {isa = PBXFileReference; lastKnownFileType = archive.zip; path = TestPasswordArchive.zip; sourceTree = "<group>"; };
+		C5AE4E63155A12760045F3ED /* IncorrectHeaders.zip */ = {isa = PBXFileReference; lastKnownFileType = archive.zip; path = IncorrectHeaders.zip; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -116,6 +118,7 @@
 			children = (
 				B215FB61143AD514003AC546 /* SSZipArchiveTests.m */,
 				B215FB5F143AD514003AC546 /* SSZipArchiveTests-Info.plist */,
+				C5AE4E63155A12760045F3ED /* IncorrectHeaders.zip */,
 				B215FB6C143AD6FF003AC546 /* TestArchive.zip */,
 				B23FCC7E1558F1B70026375C /* TestPasswordArchive.zip */,
 			);
@@ -176,6 +179,7 @@
 			files = (
 				B215FB6D143AD6FF003AC546 /* TestArchive.zip in Resources */,
 				B23FCC7F1558F1B70026375C /* TestPasswordArchive.zip in Resources */,
+				C5AE4E64155A12760045F3ED /* IncorrectHeaders.zip in Resources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Tests/SSZipArchiveTests.m

@@ -8,11 +8,14 @@
 
 #import "SSZipArchive.h"
 #import <SenTestingKit/SenTestingKit.h>
+#import <CommonCrypto/CommonDigest.h>
 
 @interface SSZipArchiveTests : SenTestCase <SSZipArchiveDelegate>
 
 - (NSString *)_cachesPath:(NSString *)directory;
 
+- (NSString *)_calculateMD5Digest:(NSData *)data;
+
 @end
 
 @implementation SSZipArchiveTests
@@ -66,6 +69,21 @@
 	STAssertTrue([fileManager fileExistsAtPath:testPath], @"LICENSE unzipped");
 }
 
+- (void)testUnzippingTruncatedFileFix {
+    NSString* zipPath = [[NSBundle bundleForClass:[self class]] pathForResource:@"IncorrectHeaders" ofType:@"zip"];
+    NSString* outputPath = [self _cachesPath:@"IncorrectHeaders"];
+    
+    [SSZipArchive unzipFileAtPath:zipPath toDestination:outputPath delegate:self];
+    
+    NSString* intendedReadmeTxtMD5 = @"31ac96301302eb388070c827447290b5";
+    
+    NSString* filePath = [outputPath stringByAppendingPathComponent:@"IncorrectHeaders/Readme.txt"];
+    NSData* data = [NSData dataWithContentsOfFile:filePath];
+    
+    NSString* actualReadmeTxtMD5 = [self _calculateMD5Digest:data];
+    STAssertTrue([actualReadmeTxtMD5 isEqualToString:intendedReadmeTxtMD5], @"Readme.txt MD5 digest should match original.");
+}
+
 
 // Commented out to avoid checking in several gig file into the repository. Simply add a file named
 // `LargeArchive.zip` to the project and uncomment out these lines to test.
@@ -117,4 +135,17 @@
 	return path;
 }
 
+- (NSString *)_calculateMD5Digest:(NSData *)data
+{
+    unsigned char buffer[CC_MD5_DIGEST_LENGTH];
+    CC_MD5([data bytes], [data length], buffer);
+    
+    NSMutableString* digest = [NSMutableString string];
+    
+    for(int i = 0; i < CC_MD5_DIGEST_LENGTH; ++i)
+        [digest appendFormat:@"%02x", buffer[i]];
+    
+    return digest;
+}
+
 @end

minizip/unzip.c

@@ -1718,10 +1718,24 @@ extern int ZEXPORT unzReadCurrentFile  (unzFile file, voidp buf, unsigned len)
 
     pfile_in_zip_read_info->stream.avail_out = (uInt)len;
 
+    // NOTE:
+    // This bit of code seems to try to set the amount of space in the output buffer based on the
+    // value stored in the headers stored in the .zip file. However, if those values are incorrect
+    // it may result in a loss of data when uncompresssing that file. The compressed data is still
+    // legit and will deflate without knowing the uncompressed code so this tidbit is unnecessary and
+    // may cause issues for some .zip files.
+    //
+    // It's removed in here to fix those issues.
+    //
+    // See: https://github.com/samsoffes/ssziparchive/issues/16
+    //
+    
+    /*
     if ((len>pfile_in_zip_read_info->rest_read_uncompressed) &&
         (!(pfile_in_zip_read_info->raw)))
         pfile_in_zip_read_info->stream.avail_out =
             (uInt)pfile_in_zip_read_info->rest_read_uncompressed;
+     */
 
     if ((len>pfile_in_zip_read_info->rest_read_compressed+
            pfile_in_zip_read_info->stream.avail_in) &&