--- Begin Message ---
Subject: |
PATH can contain non-expanded variables |
Date: |
Mon, 26 Jan 2009 14:00:15 +0100 |
Package: emacs,w32
Version: 23.0.60
It is possible for PATH (or other path-like variables, like EMACSPATH
and EMACSLOADPATH) to contain unexpanded variables:
ELISP> exec-path
("c:/emacs/bin" "%MYTEST%" "C:/WINDOWS/system32" "C:/WINDOWS"
"C:/WINDOWS/system32/Wbem" "c:/emacs/trunk/bin")
for example, if the user has set
"HKLM\Microsoft\Windows\CurrentVersion\App Paths\emacs.exe\Path" as a
REG_EXPAND_SZ.
These variables should be expanded, but currently
emacs.c:decode_env_path does not. The following patch fixes it.
Comments?
Juanma
Index: emacs.c
===================================================================
RCS file: /sources/emacs/emacs/src/emacs.c,v
retrieving revision 1.461
diff -u -2 -r1.461 emacs.c
--- emacs.c 23 Jan 2009 14:53:11 -0000 1.461
+++ emacs.c 26 Jan 2009 12:48:49 -0000
@@ -2467,6 +2467,12 @@
if (path)
{
+#ifdef WINDOWSNT
+ DWORD required = ExpandEnvironmentStrings (path, NULL, 0);
+ p = (char *) alloca (required);
+ ExpandEnvironmentStrings (path, p, required);
+#else
p = alloca (strlen (path) + 1);
strcpy (p, path);
+#endif
path = p;
--- End Message ---
--- Begin Message ---
Subject: |
Re: bug#2062: PATH can contain non-expanded variables |
Date: |
Wed, 28 Jan 2009 16:07:03 +0100 |
On Wed, Jan 28, 2009 at 15:24, Stefan Monnier <monnier@iro.umontreal.ca> wrote:
> So your patch works around a bug in some other place which fails to
> expand PATH.
Not only you're right, but I know which program is causing the problem. Thanks!
According to MSDN KB 837633 (and other sources):
Windows XP adds the path value, if it exists, to the PATH
environment variable,
if you use the ShellExecute() function to start your program.
So, correctly, Windows Explorer uses App Paths, and CMD.EXE does not
(I've checked it).
The problem is with TCC (formerly 4NT), a proprietary command shell I
use. I had mistakenly assumed that TCC worked like CMD (or, in fact, I
did the reverse: because TCC adds App Paths to PATH, I assumed that
CMD also did it).
But it is not: apparently, TCC is adding App Paths to PATH (which is
either a bug or a feature, depending of one's POV), but it's not
taking into account that the App Paths entry can be REG_EXPAND_SZ (and
that's definitely a bug).
I'll report it to them.
Juanma
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