[sword-devel] Patch for Sword crash with BibleTime on Windows

[Gary Holmlund]

Hi,

I am working on BibleTime for Windows and we found and fixed a crash in 
the sword library. I have attached a patch for the HEAD of sword svn. We 
are using the 1.60 version of sword.

The crash occurs when trying to save to a personal commentary for the 
first time. Sword is looking for the "incfile" of the personal 
commentary. The file does not exist yet.. Here is the call stack and 
function at the crash point.

libsword.dll!sword::FileDesc::read(void * buf=0x013eaec0, long count=4)  
Line 139
libsword.dll!sword::RawFiles::getNextFilename()  Line 194
libsword.dll!sword::RawFiles::setEntry(const char * inbuf=0x0253d050, 
long len=3)  Line 130
bibletime.exe!CSwordModuleInfo::write(CSwordKey * key=0x02e6cd00, const 
QString & newText={...})  Line 705

long FileDesc::read(void *buf, long count) {
   return ::read(getFd(), buf, count);       // crash here
}

Since the file does not exist, getFd() returns a  fd of -1. The read 
promptly crashes with the negative fd. Tracing the same problem in linux 
shows the same -1 fd, but the read does not crash there. The crash seems 
specific to the Visual Studio 2008 runtime libraries, but reading with a 
negative fd value is clearly wrong.

The fix is simple. Test for the negative fd and return 0 from 
fileDesc::read if fd is negative. Returning 0 is what is happening on linux.

Gary Holmlund

-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: sword_filemgr.diff
URL: <http://www.crosswire.org/pipermail/sword-devel/attachments/20091103/f3c90f35/attachment.cc>