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minizip: Fix being unable to open empty zip file

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RedworkDE 2023-02-15 12:25:33 +01:00 committed by Mark Adler
parent a566e156b3
commit f209ca7be7
1 changed files with 26 additions and 22 deletions
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48
contrib/minizip/unzip.c
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@ -379,6 +379,10 @@ extern int ZEXPORT unzStringFileNameCompare (const char* fileName1,
#define BUFREADCOMMENT (0x400)
#endif
#ifndef CENTRALDIRINVALID
#define CENTRALDIRINVALID ((ZPOS64_T)(-1))
#endif
/*
Locate the Central directory of a zipfile (at the end, just before
the global comment)
@ -388,10 +392,10 @@ local ZPOS64_T unz64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_f
ZPOS64_T uSizeFile;
ZPOS64_T uBackRead;
ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
ZPOS64_T uPosFound=0;
ZPOS64_T uPosFound=CENTRALDIRINVALID;
if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
return 0;
return CENTRALDIRINVALID;
uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
@ -401,7 +405,7 @@ local ZPOS64_T unz64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_f
buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
if (buf==NULL)
return 0;
return CENTRALDIRINVALID;
uBackRead = 4;
while (uBackRead<uMaxBack)
@ -431,7 +435,7 @@ local ZPOS64_T unz64local_SearchCentralDir(const zlib_filefunc64_32_def* pzlib_f
break;
}
if (uPosFound!=0)
if (uPosFound!=CENTRALDIRINVALID)
break;
}
TRYFREE(buf);
@ -449,12 +453,12 @@ local ZPOS64_T unz64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib
ZPOS64_T uSizeFile;
ZPOS64_T uBackRead;
ZPOS64_T uMaxBack=0xffff; /* maximum size of global comment */
ZPOS64_T uPosFound=0;
ZPOS64_T uPosFound=CENTRALDIRINVALID;
uLong uL;
ZPOS64_T relativeOffset;
if (ZSEEK64(*pzlib_filefunc_def,filestream,0,ZLIB_FILEFUNC_SEEK_END) != 0)
return 0;
return CENTRALDIRINVALID;
uSizeFile = ZTELL64(*pzlib_filefunc_def,filestream);
@ -464,7 +468,7 @@ local ZPOS64_T unz64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib
buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
if (buf==NULL)
return 0;
return CENTRALDIRINVALID;
uBackRead = 4;
while (uBackRead<uMaxBack)
@ -494,47 +498,47 @@ local ZPOS64_T unz64local_SearchCentralDir64(const zlib_filefunc64_32_def* pzlib
break;
}
if (uPosFound!=0)
if (uPosFound!=CENTRALDIRINVALID)
break;
}
TRYFREE(buf);
if (uPosFound == 0)
return 0;
if (uPosFound == CENTRALDIRINVALID)
return CENTRALDIRINVALID;
/* Zip64 end of central directory locator */
if (ZSEEK64(*pzlib_filefunc_def,filestream, uPosFound,ZLIB_FILEFUNC_SEEK_SET)!=0)
return 0;
return CENTRALDIRINVALID;
/* the signature, already checked */
if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
return 0;
return CENTRALDIRINVALID;
/* number of the disk with the start of the zip64 end of central directory */
if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
return 0;
return CENTRALDIRINVALID;
if (uL != 0)
return 0;
return CENTRALDIRINVALID;
/* relative offset of the zip64 end of central directory record */
if (unz64local_getLong64(pzlib_filefunc_def,filestream,&relativeOffset)!=UNZ_OK)
return 0;
return CENTRALDIRINVALID;
/* total number of disks */
if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
return 0;
return CENTRALDIRINVALID;
if (uL != 1)
return 0;
return CENTRALDIRINVALID;
/* Goto end of central directory record */
if (ZSEEK64(*pzlib_filefunc_def,filestream, relativeOffset,ZLIB_FILEFUNC_SEEK_SET)!=0)
return 0;
return CENTRALDIRINVALID;
/* the signature */
if (unz64local_getLong(pzlib_filefunc_def,filestream,&uL)!=UNZ_OK)
return 0;
return CENTRALDIRINVALID;
if (uL != 0x06064b50)
return 0;
return CENTRALDIRINVALID;
return relativeOffset;
}
@ -587,7 +591,7 @@ local unzFile unzOpenInternal(const void *path,
return NULL;
central_pos = unz64local_SearchCentralDir64(&us.z_filefunc,us.filestream);
if (central_pos)
if (central_pos!=CENTRALDIRINVALID)
{
uLong uS;
ZPOS64_T uL64;
@ -649,7 +653,7 @@ local unzFile unzOpenInternal(const void *path,
else
{
central_pos = unz64local_SearchCentralDir(&us.z_filefunc,us.filestream);
if (central_pos==0)
if (central_pos==CENTRALDIRINVALID)
err=UNZ_ERRNO;
us.isZip64 = 0;