[Python-checkins] r54644 - in python/trunk: Lib/distutils/msvccompiler.py Misc/NEWS

[neal.norwitz]

Author: neal.norwitz
Date: Sun Apr  1 20:24:22 2007
New Revision: 54644

Modified:
   python/trunk/Lib/distutils/msvccompiler.py
   python/trunk/Misc/NEWS
Log:
SF #1685563, MSVCCompiler creates redundant and long PATH strings

If MSVCCompiler.initialize() was called multiple times, the path
would get duplicated.  On Windows, this is a problem because the
path is limited to 4k.  There's no benefit in adding a path multiple
times, so prevent that from occuring.  We also normalize the path
before checking for duplicates so things like /a and /a/ won't both
be stored.

Will backport.


Modified: python/trunk/Lib/distutils/msvccompiler.py
==============================================================================
--- python/trunk/Lib/distutils/msvccompiler.py	(original)
+++ python/trunk/Lib/distutils/msvccompiler.py	Sun Apr  1 20:24:22 2007
@@ -187,6 +187,19 @@
     j = string.find(sys.version, ")", i)
     return sys.version[i+len(prefix):j]
 
+def normalize_and_reduce_paths(paths):
+    """Return a list of normalized paths with duplicates removed.
+
+    The current order of paths is maintained.
+    """
+    # Paths are normalized so things like:  /a and /a/ aren't both preserved.
+    reduced_paths = []
+    for p in paths:
+        np = os.path.normpath(p)
+        # XXX(nnorwitz): O(n**2), if reduced_paths gets long perhaps use a set.
+        if np not in reduced_paths:
+            reduced_paths.append(np)
+    return reduced_paths
 
 
 class MSVCCompiler (CCompiler) :
@@ -270,6 +283,7 @@
                 self.__paths.append(p)
         except KeyError:
             pass
+        self.__paths = normalize_and_reduce_paths(self.__paths)
         os.environ['path'] = string.join(self.__paths, ';')
 
         self.preprocess_options = None

Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Sun Apr  1 20:24:22 2007
@@ -1,4 +1,4 @@
-__init+++++++++++
++++++++++++
 Python News
 +++++++++++
 
@@ -200,6 +200,8 @@
 Library
 -------
 
+- Patch #1685563: remove (don't add) duplicate paths in distutils.MSVCCompiler.
+
 - Added a timeout parameter to the constructor of other protocols
   (telnetlib, ftplib, smtplib and poplib). This is second part of the
   work started with create_connection() and timeout in httplib, and