gnu: sendgmail: Don't limit domain name of sender.

There are three open pull requests adding this functionality:

  - https://github.com/google/gmail-oauth2-tools/pull/17 (October 2019)
  - https://github.com/google/gmail-oauth2-tools/pull/26 (May 2020)
  - https://github.com/google/gmail-oauth2-tools/pull/37 (May 2021)
    (The patch here is identical to #26, so I just closed this one.)

Meanwhile, the most recent commit to the upstream repository was in
May 2019: that was the commit that first added `sendgmail`.

This commit adjusts Guix's `sendgmail`, following Postel's advice,
to make the command "liberal in its receiving behavior" (RFC 760):
it always accepts email addresses with any domain name, as in #26,
and it accepts (and ignores) the `-gsuite` flag used in #17.

* gnu/packages/patches/sendgmail-remove-domain-restriction.patch:
New file. This is the patch from #26.
* gnu/packages/patches/sendgmail-accept-ignored-gsuite-flag.patch:
New file, based on #17.
* gnu/local.mk (dist_patch_DATA): Add the new patches.
* gnu/packages/mail.scm (sendgmail)[source]: Apply the new patches.
Increment the "revision" argument to `git-version` from 0 to 1.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/local.mk

@@ -1760,6 +1760,8 @@ dist_patch_DATA =						\
   %D%/packages/patches/screen-hurd-path-max.patch		\
   %D%/packages/patches/sdl-libx11-1.6.patch			\
   %D%/packages/patches/seed-webkit.patch			\
+  %D%/packages/patches/sendgmail-accept-ignored-gsuite-flag.patch	\
+  %D%/packages/patches/sendgmail-remove-domain-restriction.patch	\
   %D%/packages/patches/seq24-rename-mutex.patch			\
   %D%/packages/patches/serf-python3.patch			\
   %D%/packages/patches/shakespeare-spl-fix-grammar.patch		\

gnu/packages/mail.scm

@@ -4661,7 +4661,7 @@ (define-public rss2email
 
 (define-public sendgmail
   (let ((commit "e3229155a4037267ce40f1a3a681f53221aa4d8d")
-        (revision "0"))
+        (revision "1"))
     (package
       (name "sendgmail")
       (version (git-version "0.0.0" revision commit))
@@ -4672,6 +4672,9 @@ (define-public sendgmail
                (url "https://github.com/google/gmail-oauth2-tools")
                (commit commit)))
          (file-name (git-file-name name version))
+         (patches (search-patches
+                   "sendgmail-remove-domain-restriction.patch"
+                   "sendgmail-accept-ignored-gsuite-flag.patch"))
          (sha256
           (base32
            "1cxpkiaajhq1gjsg47r2b5xgck0r63pvkyrkm7af8c8dw7fyn64f"))))
@@ -4691,5 +4694,9 @@ (define-public sendgmail
        "The @command{sendgmail} command provides a minimal sendmail-compatible
 front-end that connects to Gmail using OAuth2.  It is specifically designed
 for use with @code{git send-email}.  The command needs a Gmail API key to
-function.")
+function.
+
+Guix's version of @command{sendgmail} has been patched for compatibility with
+all known forks, including support for non-@code{@@gmail.com} email
+addresses.")
       (license license:asl2.0))))

gnu/packages/patches/sendgmail-accept-ignored-gsuite-flag.patch

@@ -0,0 +1,39 @@
+From 854490dc4a8a6a661b4750730c3ff749519f6e36 Mon Sep 17 00:00:00 2001
+From: Philip McGrath <philip@philipmcgrath.com>
+Date: Sun, 14 Nov 2021 10:14:24 -0500
+Subject: [PATCH] sendgmail: accept and ignore a "-gsuite" flag
+
+Accepting a "-gsuite" flag provides compatability with
+https://github.com/Flameeyes/gmail-oauth2-tools/commit/eabb456
+so users do not have to change their scripts or config files.
+
+Full hash of original: eabb45608ff4ce04045ff4ea92d05450e789ac81
+
+Related to https://github.com/google/gmail-oauth2-tools/pull/17
+---
+ go/sendgmail/main.go | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/go/sendgmail/main.go b/go/sendgmail/main.go
+index 405aa1b..5cfd0c1 100644
+--- a/go/sendgmail/main.go
++++ b/go/sendgmail/main.go
+@@ -40,6 +40,7 @@ var (
+ 	setUp  bool
+ 	dummyF string
+ 	dummyI bool
++	gsuite bool
+ )
+ 
+ func init() {
+@@ -47,6 +48,7 @@ func init() {
+ 	flag.BoolVar(&setUp, "setup", false, "If true, sendgmail sets up the sender's OAuth2 token and then exits.")
+ 	flag.StringVar(&dummyF, "f", "", "Dummy flag for compatibility with sendmail.")
+ 	flag.BoolVar(&dummyI, "i", true, "Dummy flag for compatibility with sendmail.")
++	flag.BoolVar(&gsuite, "gsuite", true, "Dummy flag for compatibility with other forks of sendgmail.")
+ }
+ 
+ func main() {
+-- 
+2.32.0
+

gnu/packages/patches/sendgmail-remove-domain-restriction.patch

@@ -0,0 +1,34 @@
+From a5ecd1b2302d0def2f6f8349747022a615a9f017 Mon Sep 17 00:00:00 2001
+From: Tamas K Lengyel <tamas@tklengyel.com>
+Date: Tue, 26 May 2020 13:27:50 -0600
+Subject: [PATCH] Don't limit to email with @gmail.com
+
+---
+ go/sendgmail/main.go | 4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/go/sendgmail/main.go b/go/sendgmail/main.go
+index b35ef23..405aa1b 100644
+--- a/go/sendgmail/main.go
++++ b/go/sendgmail/main.go
+@@ -30,7 +30,6 @@ import (
+ 	"log"
+ 	"net/smtp"
+ 	"os"
+-	"strings"
+ 
+ 	"golang.org/x/oauth2"
+ 	googleOAuth2 "golang.org/x/oauth2/google"
+@@ -52,9 +51,6 @@ func init() {
+ 
+ func main() {
+ 	flag.Parse()
+-	if atDomain := "@gmail.com"; !strings.HasSuffix(sender, atDomain) {
+-		log.Fatalf("-sender must specify an %v email address.", atDomain)
+-	}
+ 	config := getConfig()
+ 	tokenPath := fmt.Sprintf("%v/.sendgmail.%v.json", os.Getenv("HOME"), sender)
+ 	if setUp {
+-- 
+2.32.0
+