bug#18515: 24.3; Documentation of `call-process'

[npostavs]

Eli Zaretskii <eliz@gnu.org> writes:

>> >> +The process runs in `default-directory'.
>> >
>> > That's not true if `default-directory' is remote.
>> 
>> Aha, good point.  This is an important thing to document.
>
> I think at least the manual should say that the default-directory
> alluded to here is that of the buffer which is current when the
> respective functions are called.

Hmm, seems a bit obvious to me, but okay.

>From d750ec77e3f15c1cf4e94e288e097bc75904e5bd Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Sat, 1 Apr 2017 23:15:46 -0400
Subject: [PATCH v3] Mention that processes start in default-directory
 (Bug#18515)

* doc/lispref/processes.texi (Synchronous Processes):
(Asynchronous Processes):
* lisp/subr.el (start-process):
* src/callproc.c (call-process): Mention that the subprocess starts in
`default-directory' when local, suggest `start-file-process' and
`process-file' otherwise.
---
 doc/lispref/processes.texi | 13 +++++++++++--
 lisp/subr.el               |  7 ++++++-
 src/callproc.c             |  4 ++++
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/doc/lispref/processes.texi b/doc/lispref/processes.texi
index 2a79cc781f..2acb7c99e0 100644
--- a/doc/lispref/processes.texi
+++ b/doc/lispref/processes.texi
@@ -300,8 +300,11 @@ Synchronous Processes
 @defun call-process program &optional infile destination display &rest args
 This function calls @var{program} and waits for it to finish.
 
-The current working directory of the subprocess is
-@code{default-directory}.
+The current working directory of the subprocess is set to the current
+buffer's value of @code{default-directory} if that is local (as
+determined by @code{unhandled-file-name-directory}), or "~" otherwise.
+If you want to run a process in a remote directory use
+@code{process-file}.
 
 The standard input for the new process comes from file @var{infile} if
 @var{infile} is not @code{nil}, and from the null device otherwise.
@@ -677,6 +680,12 @@ Asynchronous Processes
 
 The original argument list, modified with the actual connection
 information, is available via the @code{process-contact} function.
+
+The current working directory of the subprocess is set to the current
+buffer's value of @code{default-directory} if that is local (as
+determined by `unhandled-file-name-directory'), or "~" otherwise.  If
+you want to run a process in a remote direcotry use
+@code{start-file-process}.
 @end defun
 
 @defun make-pipe-process &rest args
diff --git a/lisp/subr.el b/lisp/subr.el
index ebac2e0ef5..472f931306 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -1970,7 +1970,12 @@ start-process
 
 If you want to separate standard output from standard error, use
 `make-process' or invoke the command through a shell and redirect
-one of them using the shell syntax."
+one of them using the shell syntax.
+
+The process runs in `default-directory' if that is local (as
+determined by `unhandled-file-name-directory'), or \"~\"
+otherwise.  If you want to run a process in a remote directory
+use `start-file-process'."
   (unless (fboundp 'make-process)
     (error "Emacs was compiled without subprocess support"))
   (apply #'make-process
diff --git a/src/callproc.c b/src/callproc.c
index 6d69e13757..a781e47b17 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -240,6 +240,10 @@ t (mix it with ordinary output), or a file name string.
 and returns a numeric exit status or a signal description string.
 If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.
 
+The process runs in `default-directory' if that is local (as
+determined by `unhandled-file-name-directory'), or "~" otherwise.  If
+you want to run a process in a remote directory use `process-file'.
+
 usage: (call-process PROGRAM &optional INFILE DESTINATION DISPLAY &rest ARGS)  
*/)
   (ptrdiff_t nargs, Lisp_Object *args)
 {
-- 
2.11.1