send-email: avoid creating more than one Term::ReadLine object

Every time git-send-email calls its ask() function to prompt the user,
we call term(), which instantiates a new Term::ReadLine object. But in
v1.46 of Term::ReadLine::Gnu (which provides the Term::ReadLine
interface on some platforms), its constructor refuses to create a second
instance[1]. So on systems with that version of the module, most
git-send-email instances will fail (as we usually prompt for both "to"
and "in-reply-to" unless the user provided them on the command line).

We can fix this by keeping a single instance variable and returning it
for each call to term(). In perl 5.10 and up, we could do that with a
"state" variable. But since we only require 5.008, we'll do it the
old-fashioned way, with a lexical "my" in its own scope.

Note that the tests in t9001 detect this problem as-is, since the
failure mode is for the program to die. But let's also beef up the
"Prompting works" test to check that it correctly handles multiple
inputs (if we had chosen to keep our FakeTerm hack in the previous
commit, then the failure mode would be incorrectly ignoring prompts
after the first).

[1] For discussion of why multiple instances are forbidden, see:
    https://github.com/hirooih/perl-trg/issues/16

[jc: cherry-picked from v2.42.0-rc2~6^2]

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-send-email.perl b/git-send-email.perl
index 72d876f0a044fcec0f310e61c193d3f2bfcb9af0..ad51508790547aef275ab41b61fafe341da11f5c 100755 (executable)
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -917,11 +917,19 @@ EOT3
        do_edit(@files);
 }
 
-sub term {
-       require Term::ReadLine;
-       return $ENV{"GIT_SEND_EMAIL_NOTTY"}
-                       ? Term::ReadLine->new('git-send-email', \*STDIN, \*STDOUT)
-                       : Term::ReadLine->new('git-send-email');
+{
+       # Only instantiate one $term per program run, since some
+       # Term::ReadLine providers refuse to create a second instance.
+       my $term;
+       sub term {
+               require Term::ReadLine;
+               if (!defined $term) {
+                       $term = $ENV{"GIT_SEND_EMAIL_NOTTY"}
+                               ? Term::ReadLine->new('git-send-email', \*STDIN, \*STDOUT)
+                               : Term::ReadLine->new('git-send-email');
+               }
+               return $term;
+       }
 }
 
 sub ask {

diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 1130ef21b342a83f02f7d5865fa726b80fd4ce01..0f08a9542b3cd3af6bafe90eea0f2a86e3546fb0 100755 (executable)
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -337,13 +337,14 @@ test_expect_success $PREREQ 'Show all headers' '
 test_expect_success $PREREQ 'Prompting works' '
        clean_fake_sendmail &&
        (echo "to@example.com" &&
-        echo ""
+        echo "my-message-id@example.com"
        ) | GIT_SEND_EMAIL_NOTTY=1 git send-email \
                --smtp-server="$(pwd)/fake.sendmail" \
                $patches \
                2>errors &&
                grep "^From: A U Thor <author@example.com>\$" msgtxt1 &&
-               grep "^To: to@example.com\$" msgtxt1
+               grep "^To: to@example.com\$" msgtxt1 &&
+               grep "^In-Reply-To: <my-message-id@example.com>" msgtxt1
 '
 
 test_expect_success $PREREQ,AUTOIDENT 'implicit ident is allowed' '