Backport:

Fix for SF bug 601077 by Zack Weinberg.

The new execvpe code would sometimes do the wrong thing when a
non-executable file existed earlier in the path and an executable file
of the same name existed later in the path.  This patch restores the
proper behavior (which is to execute the second file).  When only a
non-executable file exists, the correct error is still reported.

diff --git a/Lib/os.py b/Lib/os.py
index 6463e389dd9a353fae07f1f52a3aa0e7d7b24daa..b9969c708f90073d3a3134fcb7d39ebd767ef05a 100644 (file)
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -298,7 +298,7 @@ def execvp(file, args):
     _execvpe(file, args)
 
 def execvpe(file, args, env):
-    """execv(file, args, env)
+    """execvpe(file, args, env)
 
     Execute the executable file (which is searched for along $PATH)
     with argument list args and environment env , replacing the
@@ -328,14 +328,21 @@ def _execvpe(file, args, env=None):
     else:
         envpath = defpath
     PATH = envpath.split(pathsep)
+    saved_exc = None
+    saved_tb = None
     for dir in PATH:
         fullname = path.join(dir, file)
         try:
             apply(func, (fullname,) + argrest)
-        except error, (errno, msg):
-            if errno != ENOENT and errno != ENOTDIR:
-                raise
-    raise error, (errno, msg)
+        except error, e:
+            tb = sys.exc_info()[2]
+            if (e.errno != ENOENT and e.errno != ENOTDIR
+                and saved_exc is None):
+                saved_exc = e
+                saved_tb = tb
+    if saved_exc:
+        raise error, saved_exc, saved_tb
+    raise error, e, tb
 
 # Change environ to automatically call putenv() if it exists
 try: