Bug 792135 - Part 1: Add which Python package; r=glandium

Version 1.1.0 obtained from https://code.google.com/p/which/ and added
to tree without modifications aside from the removal of which.exe, which
has no reason to be in the tree.

python/which/test/testsupport.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+# Copyright (c) 2002-2003 ActiveState Corp.
+# Author: Trent Mick (TrentM@ActiveState.com)
+
+import os
+import sys
+import types
+
+
+#---- Support routines
+
+def _escapeArg(arg):
+    """Escape the given command line argument for the shell."""
+    #XXX There is a *lot* more that we should escape here.
+    return arg.replace('"', r'\"')
+
+
+def _joinArgv(argv):
+    r"""Join an arglist to a string appropriate for running.
+        >>> import os
+        >>> _joinArgv(['foo', 'bar "baz'])
+        'foo "bar \\"baz"'
+    """
+    cmdstr = ""
+    for arg in argv:
+        if ' ' in arg:
+            cmdstr += '"%s"' % _escapeArg(arg)
+        else:
+            cmdstr += _escapeArg(arg)
+        cmdstr += ' '
+    if cmdstr.endswith(' '): cmdstr = cmdstr[:-1]  # strip trailing space
+    return cmdstr
+
+
+def run(argv):
+    """Prepare and run the given arg vector, 'argv', and return the
+    results.  Returns (<stdout lines>, <stderr lines>, <return value>).
+    Note: 'argv' may also just be the command string.
+    """
+    if type(argv) in (types.ListType, types.TupleType):
+        cmd = _joinArgv(argv)
+    else:
+        cmd = argv
+    if sys.platform.startswith('win'):
+        i, o, e = os.popen3(cmd)
+        output = o.read()
+        error = e.read()
+        i.close()
+        e.close()
+        try:
+            retval = o.close()
+        except IOError:
+            # IOError is raised iff the spawned app returns -1. Go
+            # figure.
+            retval = -1 
+        if retval is None:
+            retval = 0
+    else:
+        import popen2
+        p = popen2.Popen3(cmd, 1)
+        i, o, e = p.tochild, p.fromchild, p.childerr
+        output = o.read()
+        error = e.read()
+        i.close()
+        o.close()
+        e.close()
+        retval = (p.wait() & 0xFF00) >> 8
+        if retval > 2**7: # 8-bit signed 1's-complement conversion
+            retval -= 2**8
+    return output, error, retval
+
+
+def _rmtreeOnError(rmFunction, filePath, excInfo):
+    if excInfo[0] == OSError:
+        # presuming because file is read-only
+        os.chmod(filePath, 0777)
+        rmFunction(filePath)
+
+def rmtree(dirname):
+    import shutil
+    shutil.rmtree(dirname, 0, _rmtreeOnError)
+
+