[Python-checkins] CVS: python/dist/src/PC getpathp.c,1.24,1.25

[Mark Hammond]

Update of /cvsroot/python/python/dist/src/PC
In directory usw-pr-cvs1:/tmp/cvs-serv18370

Modified Files:
	getpathp.c 
Log Message:
Fix bug #410274 - sys.prefix isn't always set.

If after calculating sys.path we do not have sys.prefix set, we loop over all path entries checking if one can point to our home directory.

Index: getpathp.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/PC/getpathp.c,v
retrieving revision 1.24
retrieving revision 1.25
diff -C2 -d -r1.24 -r1.25
*** getpathp.c	2001/07/23 16:30:27	1.24
--- getpathp.c	2001/09/07 14:08:01	1.25
***************
*** 45,49 ****
    * When Python is hosted in another exe (different directory, embedded via 
      COM, etc), the Python Home will not be deduced, so the core path from
!     the registry is used.  Other "application paths "in the registry are 
      always read.
  
--- 45,49 ----
    * When Python is hosted in another exe (different directory, embedded via 
      COM, etc), the Python Home will not be deduced, so the core path from
!     the registry is used.  Other "application paths" in the registry are 
      always read.
  
***************
*** 577,580 ****
--- 577,614 ----
  	}
  	*buf = '\0';
+ 	/* Now to pull one last hack/trick.  If sys.prefix is
+ 	   empty, then try and find it somewhere on the paths
+ 	   we calculated.  We scan backwards, as our general policy
+ 	   is that Python core directories are at the *end* of
+ 	   sys.path.  We assume that our "lib" directory is
+ 	   on the path, and that our 'prefix' directory is
+ 	   the parent of that.
+ 	*/
+ 	if (*prefix=='\0') {
+ 		char lookBuf[MAXPATHLEN+1];
+ 		char *look = buf - 1; /* 'buf' is at the end of the buffer */
+ 		while (1) {
+ 			int nchars;
+ 			char *lookEnd = look;
+ 			/* 'look' will end up one character before the
+ 			   start of the path in question - even if this
+ 			   is one character before the start of the buffer
+ 			*/
+ 			while (*look != DELIM && look >= module_search_path)
+ 				look--;
+ 			nchars = lookEnd-look;
+ 			strncpy(lookBuf, look+1, nchars);
+ 			lookBuf[nchars] = '\0';
+ 			/* Up one level to the parent */
+ 			reduce(lookBuf);
+ 			if (search_for_prefix(lookBuf, LANDMARK)) {
+ 				break;
+ 			}
+ 			/* If we are out of paths to search - give up */
+ 			if (look < module_search_path)
+ 				break;
+ 			look--;
+ 		}
+ 	}
  }