bug#58813: [PATCH 1/5] gnu: git: Apply patch adding the --header-cmd feature.

[Maxim Cournoyer]

In preparation to fix <https://issues.guix.gnu.org/58813>.

* gnu/packages/patches/git-header-cmd.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/version-control.scm (git) [source]: Apply patch.
---
 gnu/local.mk                              |   1 +
 gnu/packages/patches/git-header-cmd.patch | 180 ++++++++++++++++++++++
 gnu/packages/version-control.scm          |   3 +-
 3 files changed, 183 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/git-header-cmd.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index b631fa6d5a..d7c7ca48e7 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1209,6 +1209,7 @@ dist_patch_DATA =                                         
\
   %D%/packages/patches/gemmi-fix-sajson-types.patch            \
   %D%/packages/patches/genimage-mke2fs-test.patch              \
   %D%/packages/patches/geoclue-config.patch                    \
+  %D%/packages/patches/git-header-cmd.patch                    \
   %D%/packages/patches/ghc-8.0-fall-back-to-madv_dontneed.patch        \
   %D%/packages/patches/ghc-9.2-glibc-2.33-link-order.patch \
   %D%/packages/patches/ghc-testsuite-dlopen-pie.patch          \
diff --git a/gnu/packages/patches/git-header-cmd.patch 
b/gnu/packages/patches/git-header-cmd.patch
new file mode 100644
index 0000000000..fdd34fe4a4
--- /dev/null
+++ b/gnu/packages/patches/git-header-cmd.patch
@@ -0,0 +1,180 @@
+Add a '--header-cmd' to git send-email.
+
+Upstream status can be tracked at:
+https://lore.kernel.org/git/20230423122744.4865-1-maxim.cournoyer@gmail.com/T/#t
+
+diff --git a/Documentation/config/sendemail.txt 
b/Documentation/config/sendemail.txt
+index 51da7088a8..3d0f516520 100644
+--- a/Documentation/config/sendemail.txt
++++ b/Documentation/config/sendemail.txt
+@@ -58,6 +58,7 @@ sendemail.annotate::
+ sendemail.bcc::
+ sendemail.cc::
+ sendemail.ccCmd::
++sendemail.headerCmd::
+ sendemail.chainReplyTo::
+ sendemail.envelopeSender::
+ sendemail.from::
+diff --git a/Documentation/git-send-email.txt 
b/Documentation/git-send-email.txt
+index b0f438ec99..354c0d06db 100644
+--- a/Documentation/git-send-email.txt
++++ b/Documentation/git-send-email.txt
+@@ -320,6 +320,11 @@ Automating
+       Output of this command must be single email address per line.
+       Default is the value of `sendemail.ccCmd` configuration value.
+ 
++--header-cmd=<command>::
++      Specify a command to execute once per patch file which should
++      generate arbitrary, patch file specific header entries.
++      Default is the value of `sendemail.headerCmd` configuration value.
++
+ --[no-]chain-reply-to::
+       If this is set, each email will be sent as a reply to the previous
+       email sent.  If disabled with "--no-chain-reply-to", all emails after
+diff --git a/git-send-email.perl b/git-send-email.perl
+index fd8cd0d46f..676dd83d89 100755
+--- a/git-send-email.perl
++++ b/git-send-email.perl
+@@ -2,6 +2,7 @@
+ #
+ # Copyright 2002,2005 Greg Kroah-Hartman <greg@kroah.com>
+ # Copyright 2005 Ryan Anderson <ryan@michonline.com>
++# Copyright 2023 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+ #
+ # GPL v2 (See COPYING)
+ #
+@@ -87,8 +88,9 @@ sub usage {
+ 
+   Automating:
+     --identity              <str>  * Use the sendemail.<id> options.
+-    --to-cmd                <str>  * Email To: via `<str> \$patch_path`
+-    --cc-cmd                <str>  * Email Cc: via `<str> \$patch_path`
++    --to-cmd                <str>  * Email To: via `<str> \$patch_path`.
++    --cc-cmd                <str>  * Email Cc: via `<str> \$patch_path`.
++    --header-cmd            <str>  * Add headers via `<str> \$patch_path`.
+     --suppress-cc           <str>  * author, self, sob, cc, cccmd, body, 
bodycc, misc-by, all.
+     --[no-]cc-cover                * Email Cc: addresses in the cover letter.
+     --[no-]to-cover                * Email To: addresses in the cover letter.
+@@ -269,7 +271,7 @@ sub do_edit {
+ # Variables with corresponding config settings
+ my ($suppress_from, $signed_off_by_cc);
+ my ($cover_cc, $cover_to);
+-my ($to_cmd, $cc_cmd);
++my ($to_cmd, $cc_cmd, $header_cmd);
+ my ($smtp_server, $smtp_server_port, @smtp_server_options);
+ my ($smtp_authuser, $smtp_encryption, $smtp_ssl_cert_path);
+ my ($batch_size, $relogin_delay);
+@@ -318,6 +320,7 @@ sub do_edit {
+     "tocmd" => \$to_cmd,
+     "cc" => \@config_cc,
+     "cccmd" => \$cc_cmd,
++    "headercmd" => \$header_cmd,
+     "aliasfiletype" => \$aliasfiletype,
+     "bcc" => \@config_bcc,
+     "suppresscc" => \@suppress_cc,
+@@ -519,6 +522,7 @@ sub config_regexp {
+                   "compose" => \$compose,
+                   "quiet" => \$quiet,
+                   "cc-cmd=s" => \$cc_cmd,
++                  "header-cmd=s" => \$header_cmd,
+                   "suppress-from!" => \$suppress_from,
+                   "no-suppress-from" => sub {$suppress_from = 0},
+                   "suppress-cc=s" => \@suppress_cc,
+@@ -1776,6 +1780,9 @@ sub process_file {
+                       push(@header, $_);
+               }
+       }
++      # Add computed headers, if applicable.
++      push @header, execute_cmd("header-cmd", $header_cmd, $t)
++              if defined $header_cmd;
+       # Now parse the header
+       foreach(@header) {
+               if (/^From /) {
+@@ -2006,15 +2013,30 @@ sub process_file {
+       }
+ }
+ 
++# Execute a command (e.g., $x_cmd) and return its output lines as an
++# array.
++sub execute_cmd {
++      my ($prefix, $cmd, $file) = @_;
++      my @lines = ();
++      open my $fh, "-|", "$cmd \Q$file\E"
++              or die sprintf(__("(%s) Could not execute '%s'"), $prefix, 
$cmd);
++      while (my $line = <$fh>) {
++              last if $line =~ /^$/;
++              push @lines, $line;
++      }
++      close $fh
++          or die sprintf(__("(%s) failed to close pipe to '%s'"), $prefix, 
$cmd);
++      return @lines;
++}
++
+ # Execute a command (e.g. $to_cmd) to get a list of email addresses
+ # and return a results array
+ sub recipients_cmd {
+       my ($prefix, $what, $cmd, $file) = @_;
+-
++      my @lines = ();
+       my @addresses = ();
+-      open my $fh, "-|", "$cmd \Q$file\E"
+-          or die sprintf(__("(%s) Could not execute '%s'"), $prefix, $cmd);
+-      while (my $address = <$fh>) {
++      @lines = execute_cmd($prefix, $cmd, $file);
++      for my $address (@lines) {
+               $address =~ s/^\s*//g;
+               $address =~ s/\s*$//g;
+               $address = sanitize_address($address);
+@@ -2023,8 +2045,6 @@ sub recipients_cmd {
+               printf(__("(%s) Adding %s: %s from: '%s'\n"),
+                      $prefix, $what, $address, $cmd) unless $quiet;
+               }
+-      close $fh
+-          or die sprintf(__("(%s) failed to close pipe to '%s'"), $prefix, 
$cmd);
+       return @addresses;
+ }
+ 
+diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
+index 0de83b5d2b..3393725107 100755
+--- a/t/t9001-send-email.sh
++++ b/t/t9001-send-email.sh
+@@ -374,13 +374,16 @@ test_expect_success $PREREQ,!AUTOIDENT 'broken implicit 
ident aborts send-email'
+       )
+ '
+ 
+-test_expect_success $PREREQ 'setup tocmd and cccmd scripts' '
++test_expect_success $PREREQ 'setup cmd scripts' '
+       write_script tocmd-sed <<-\EOF &&
+       sed -n -e "s/^tocmd--//p" "$1"
+       EOF
+-      write_script cccmd-sed <<-\EOF
++      write_script cccmd-sed <<-\EOF &&
+       sed -n -e "s/^cccmd--//p" "$1"
+       EOF
++      write_script headercmd-sed <<-\EOF
++      sed -n -e "s/^headercmd--//p" "$1"
++      EOF
+ '
+ 
+ test_expect_success $PREREQ 'tocmd works' '
+@@ -410,6 +413,20 @@ test_expect_success $PREREQ 'cccmd works' '
+       grep "^ cccmd@example.com" msgtxt1
+ '
+ 
++test_expect_success $PREREQ 'headercmd works' '
++      clean_fake_sendmail &&
++      cp $patches headercmd.patch &&
++      echo "headercmd--X-Debbugs-CC: dummy@example.com" >>headercmd.patch &&
++      git send-email \
++              --from="Example <nobody@example.com>" \
++              --to=nobody@example.com \
++              --header-cmd=./headercmd-sed \
++              --smtp-server="$(pwd)/fake.sendmail" \
++              headercmd.patch \
++              &&
++      grep "^X-Debbugs-CC: dummy@example.com" msgtxt1
++'
++
+ test_expect_success $PREREQ 'reject long lines' '
+       z8=zzzzzzzz &&
+       z64=$z8$z8$z8$z8$z8$z8$z8$z8 &&
diff --git a/gnu/packages/version-control.scm b/gnu/packages/version-control.scm
index 302f7c90ad..d5d88b99ed 100644
--- a/gnu/packages/version-control.scm
+++ b/gnu/packages/version-control.scm
@@ -232,7 +232,8 @@ (define-public git
                                 version ".tar.xz"))
             (sha256
              (base32
-              "1mpjvhyw8mv2q941xny4d0gw3mb6b4bqaqbh73jd8b1v6zqpaps7"))))
+              "1mpjvhyw8mv2q941xny4d0gw3mb6b4bqaqbh73jd8b1v6zqpaps7"))
+            (patches (search-patches "git-header-cmd.patch"))))
    (build-system gnu-build-system)
    (native-inputs
     `(("native-perl" ,perl)
-- 
2.39.2