[PATCH] send-email: do not check for editor until needed

[Jonathan Nieder <jrnieder@gmail.com>]

Since b4479f074 (add -i, send-email, svn, p4, etc: use "git var
GIT_EDITOR", 2009-10-30), when called with TERM=dumb and without
GIT_EDITOR set, git send-email has been failing whether it needs
an editor or not:

 $ ssh localhost git send-email --to=me --suppress-cc=all HEAD^..HEAD
 fatal: Terminal is dumb, but EDITOR unset
 var GIT_EDITOR: command returned error: 128

This breaks use of git send-email in existing hook scripts.

So do not check for an editor unless it is needed.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Uwe Kleine-König wrote:

> since b4479f074760a788dd4e353b8c86a7d735afc53e git send-email (and
> others) use git var GIT_EDITOR.  This is OK as such but it breaks the
> post-receive hooks that I use on several repositories.
[...]
> IMHO git send-email should only call $(git var GIT_EDITOR) when it
> actually needs it.

Thanks for reporting.  Does this patch work for you?

Now if I try without a tty, I get a different error:

 $ ssh localhost cd $(pwd) '&&' \
	git send-email --to=me --suppress-cc=all HEAD^..HEAD
 Can't locate object method "IN" via package "FakeTerm" at
 /home/jrn/tmp-git/libexec/git-core/git-send-email line 645.
 /tmp/olTiwjzrjx/0001-Git-1.7.0.3.patch

I assume I am not using it correctly, since the relevant code has
been around for a while.

 git-send-email.perl |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index e05455f..9406cdd 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -162,9 +162,16 @@ my $compose_filename;
 
 # Handle interactive edition of files.
 my $multiedit;
-my $editor = Git::command_oneline('var', 'GIT_EDITOR');
 
 sub do_edit {
+	my $editor;
+
+	if ($#_ == 0) {
+		return;
+	}
+	git_cmd_try {
+		$editor = Git::command_oneline('var', 'GIT_EDITOR');
+	} "no suitable text editor configured\n";
 	if (defined($multiedit) && !$multiedit) {
 		map {
 			system('sh', '-c', $editor.' "$@"', $editor, $_);
-- 
1.7.0.2