From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: cygwin-patches@cygwin.com
Subject: Re: [PATCH v6 4/4] Do not rely on `getenv ("HOME")`'s path conversion
Date: Thu, 6 Apr 2023 11:54:05 +0200 (CEST) [thread overview]
Message-ID: <097f16c8-9df1-4dad-6eb4-30fe090c9f05@gmx.de> (raw)
In-Reply-To: <ZC6EwQgygFo/GkNL@calimero.vinschen.de>
[-- Attachment #1: Type: text/plain, Size: 3483 bytes --]
Hi Corinna,
On Thu, 6 Apr 2023, Corinna Vinschen wrote:
> On Apr 4 17:07, Johannes Schindelin wrote:
> > In the very early code path where `dll_crt0_1 ()` calls
> > `user_shared->initialize ()`, the Cygwin runtime calls `internal_pwsid ()`
> > to initialize the user name in preparation for reading the `fstab` file.
> >
> > In case `db_home: env` is defined in `/etc/nsswitch.conf`, we need to
> > look at the environment variable `HOME` and use it, if set.
>
> I'm a bit puzzled by this. HOME is not a Windows variable. You're
> usually not supposed to set it to Windows values, but to the POSIX
> value. I'm aware that Cygwin makes the conversion, too, for historical
> reasons.
>
> But why on earth would you set a variable you have under your own
> control, and which only makes sense in a POSIX environment, to a Windows
> value?
This is actually a well-documented feature of Git for Windows, which
cannot handle Cygwin paths (at least not `git.exe`, which is a MINGW
program).
And since Git for Windows is also used in third-party software like Visual
Studio, it is quite conceivable that the `HOME` variable is intended to be
used by Git for Windows and Cygwin. I know that I will use it for both,
once a Cygwin runtime version is released with these patches.
And even if it is not Git for Windows, we are talking about system-wide
environment variables. And that system is Windows...
So yes, we absolutely have to expect the `HOME` variable to potentially
contain a Windows path.
> > When all of this happens, though, the `pinfo_init ()` function has had no
> > change to run yet (and therefore, `environ_init ()`). At this stage,
>
> chance
👍
> > therefore, `getenv ()`'s `findenv_func ()` call still finds `getearly ()`
> > and we get the _verbatim_ value of `HOME`. That is, the Windows form.
> > But we need the "POSIX" form.
> > [...]
> > Let's detect when the `HOME` value is still in Windows format in
> > `fetch_home_env ()`, and convert it in that case.
> >
> > Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> > ---
> > winsup/cygwin/uinfo.cc | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
> > index 5e2d88bcd7..bc9e926159 100644
> > --- a/winsup/cygwin/uinfo.cc
> > +++ b/winsup/cygwin/uinfo.cc
> > @@ -929,7 +929,13 @@ fetch_home_env (void)
> > /* If `HOME` is set, prefer it */
> > const char *home = getenv ("HOME");
> > if (home)
> > - return strdup (home);
> > + {
> > + /* In the very early code path of `user_info::initialize ()`, the value
> > + of the environment variable `HOME` is still in its Windows form. */
> > + if (isdrive (home))
>
> While the description is clear on the colon problem, shouldn't this
> catch UNC paths as well? I. e., just check for strchr(home, '\\')?
Good idea! I do not know off-hand how well things work when `HOME` is an
UNC path, but we can fix those things when (and if) they arrive.
I'll use `isdrive (home) || home[0] == '\\'` as is used elsewhere, okay?
Ciao,
Johannes
>
> > + return (char *) cygwin_create_path (CCP_WIN_A_TO_POSIX, home);
>
>
> > + return strdup (home);
> > + }
> >
> > /* If `HOME` is unset, fall back to `HOMEDRIVE``HOMEPATH`
> > (without a directory separator, as `HOMEPATH` starts with one). */
> > --
> > 2.40.0.windows.1
>
next prev parent reply other threads:[~2023-04-06 9:54 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-16 13:06 [PATCH] Allow overriding the home directory via the HOME variable Johannes Schindelin
2015-10-21 18:32 ` Corinna Vinschen
2015-10-22 15:38 ` Johannes Schindelin
2015-10-23 9:10 ` Corinna Vinschen
2015-10-23 9:41 ` Corinna Vinschen
2015-10-23 12:00 ` Johannes Schindelin
2015-12-17 18:05 ` [PATCH v2 0/2] Support deriving the current user's home directory via HOME Johannes Schindelin
2015-12-17 18:05 ` [PATCH v2 2/2] Respect `db_home` setting even for the SYSTEM account Johannes Schindelin
2015-12-17 20:49 ` Corinna Vinschen
2015-12-17 21:02 ` Corinna Vinschen
2022-09-21 12:00 ` Johannes Schindelin
2015-12-17 18:05 ` [PATCH v2 1/2] Allow deriving the current user's home directory via the HOME variable Johannes Schindelin
2015-12-17 20:20 ` Corinna Vinschen
2022-09-21 11:58 ` Johannes Schindelin
2022-10-18 17:02 ` Corinna Vinschen
2022-10-23 21:04 ` Johannes Schindelin
2022-10-24 11:37 ` Corinna Vinschen
2022-11-10 15:16 ` Johannes Schindelin
2022-11-10 15:22 ` Corinna Vinschen
2022-11-18 8:18 ` Johannes Schindelin
2022-11-21 11:41 ` Corinna Vinschen
2023-03-28 8:21 ` Johannes Schindelin
2022-09-21 11:51 ` [PATCH v3 0/3] Support deriving the current user's home directory via HOME Johannes Schindelin
2022-09-21 11:51 ` [PATCH v3 1/3] Allow deriving the current user's home directory via the HOME variable Johannes Schindelin
2022-09-21 11:52 ` [PATCH v3 2/3] Respect `db_home` setting even for SYSTEM/Microsoft accounts Johannes Schindelin
2022-09-21 11:52 ` [PATCH v3 3/3] Respect `db_home: env` even when no uid can be determined Johannes Schindelin
2023-03-28 8:17 ` [PATCH v4 0/3] Support deriving the current user's home directory via HOME Johannes Schindelin
2023-03-28 8:17 ` [PATCH v4 1/3] Allow deriving the current user's home directory via the HOME variable Johannes Schindelin
2023-03-28 10:35 ` Corinna Vinschen
2023-03-28 12:34 ` Jon Turney
2023-03-28 13:31 ` Corinna Vinschen
2023-03-29 8:36 ` Corinna Vinschen
2023-04-03 6:39 ` Johannes Schindelin
2023-03-28 8:17 ` [PATCH v4 2/3] Respect `db_home` setting even for SYSTEM/Microsoft accounts Johannes Schindelin
2023-03-28 10:16 ` Corinna Vinschen
2023-04-03 6:36 ` Johannes Schindelin
2023-04-03 10:59 ` Corinna Vinschen
2023-04-03 13:32 ` Johannes Schindelin
2023-03-28 8:17 ` [PATCH v4 3/3] Respect `db_home: env` even when no uid can be determined Johannes Schindelin
2023-03-28 10:17 ` Corinna Vinschen
2023-04-03 6:45 ` Johannes Schindelin
2023-04-03 13:12 ` Johannes Schindelin
2023-04-03 13:29 ` Corinna Vinschen
2023-04-03 13:57 ` Johannes Schindelin
2023-04-03 19:23 ` Corinna Vinschen
2023-04-04 15:11 ` Johannes Schindelin
2023-04-03 13:19 ` Johannes Schindelin
2023-04-03 14:44 ` [PATCH v5 0/3] Support deriving the current user's home directory via HOME Johannes Schindelin
2023-04-03 14:44 ` [PATCH v5 1/3] Allow deriving the current user's home directory via the HOME variable Johannes Schindelin
2023-04-03 18:36 ` Corinna Vinschen
2023-04-04 15:12 ` Johannes Schindelin
2023-04-03 14:45 ` [PATCH v5 2/3] Respect `db_home` setting even for SYSTEM/Microsoft accounts Johannes Schindelin
2023-04-03 18:37 ` Corinna Vinschen
2023-04-04 15:12 ` Johannes Schindelin
2023-04-03 14:45 ` [PATCH v5 3/3] Respect `db_home: env` even when no uid can be determined Johannes Schindelin
2023-04-04 15:07 ` [PATCH v6 0/4] Support deriving the current user's home directory via HOME Johannes Schindelin
2023-04-04 15:07 ` [PATCH v6 1/4] Allow deriving the current user's home directory via the HOME variable Johannes Schindelin
2023-04-04 15:07 ` [PATCH v6 2/4] Respect `db_home` setting even for SYSTEM/Microsoft accounts Johannes Schindelin
2023-04-04 15:07 ` [PATCH v6 3/4] uinfo: special-case IIS APPPOOL accounts Johannes Schindelin
2023-04-04 15:07 ` [PATCH v6 4/4] Do not rely on `getenv ("HOME")`'s path conversion Johannes Schindelin
2023-04-06 8:37 ` Corinna Vinschen
2023-04-06 9:54 ` Johannes Schindelin [this message]
2023-04-06 10:28 ` Corinna Vinschen
2023-05-22 11:12 ` [PATCH v7 0/4] Support deriving the current user's home directory via HOME Johannes Schindelin
2023-05-22 11:12 ` [PATCH v7 1/4] Allow deriving the current user's home directory via the HOME variable Johannes Schindelin
2023-05-22 11:12 ` [PATCH v7 2/4] Respect `db_home` setting even for SYSTEM/Microsoft accounts Johannes Schindelin
2023-05-22 11:12 ` [PATCH v7 3/4] uinfo: special-case IIS APPPOOL accounts Johannes Schindelin
2023-05-22 11:13 ` [PATCH v7 4/4] Do not rely on `getenv ("HOME")`'s path conversion Johannes Schindelin
2023-06-06 13:33 ` [PATCH v7 0/4] Support deriving the current user's home directory via HOME Corinna Vinschen
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