Documentation: hints for sending patches inline with Thunderbird

The standard reference for this information is the article
"Plain text e-mail - Thunderbird#Completely_plain_email" at
kb.mozillazine.org, but the hints hidden away in git's
SubmittingPatches file are more complete.  Move them to the
"git format-patch" manual so they can be installed with git and
read by a wide audience.

While at it, make some tweaks:

 - update "Approach #1" so it might work with Thunderbird 3;
 - remove ancient version numbers from the descriptions of both
   approaches so current readers might have more reason to
   complain if they don't work.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 8bf6a68501..627f381331 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -332,6 +332,89 @@ If it does not apply correctly, there can be various reasons.
   patch e-mail should come after the three-dash line that signals
   the end of the commit message.
 
+MUA-SPECIFIC HINTS
+------------------
+Here are some hints on how to successfully submit patches inline using
+various mailers.
+
+Thunderbird
+~~~~~~~~~~~
+By default, Thunderbird will both wrap emails as well as flag
+them as being 'format=flowed', both of which will make the
+resulting email unusable by git.
+
+There are two different approaches.  One approach is to configure
+Thunderbird to not mangle patches.  The second approach is to use
+an external editor to keep Thunderbird from mangling the patches.
+
+Approach #1 (configuration)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Three steps:
+
+1. Configure your mail server composition as plain text:
+   Edit...Account Settings...Composition & Addressing,
+   uncheck "Compose Messages in HTML".
+
+2. Configure your general composition window to not wrap.
++
+In Thunderbird 2:
+Edit..Preferences..Composition, wrap plain text messages at 0
++
+In Thunderbird 3:
+Edit..Preferences..Advanced..Config Editor.  Search for
+"mail.wrap_long_lines".
+Toggle it to make sure it is set to `false`.
+
+3. Disable the use of format=flowed:
+Edit..Preferences..Advanced..Config Editor.  Search for
+"mailnews.send_plaintext_flowed".
+Toggle it to make sure it is set to `false`.
+
+After that is done, you should be able to compose email as you
+otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
+and the patches will not be mangled.
+
+Approach #2 (external editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following Thunderbird extensions are needed:
+AboutConfig from http://aboutconfig.mozdev.org/ and
+External Editor from http://globs.org/articles.php?lng=en&pg=8
+
+1. Prepare the patch as a text file using your method of choice.
+
+2. Before opening a compose window, use Edit->Account Settings to
+   uncheck the "Compose messages in HTML format" setting in the
+   "Composition & Addressing" panel of the account to be used to
+   send the patch.
+
+3. In the main Thunderbird window, 'before' you open the compose
+   window for the patch, use Tools->about:config to set the
+   following to the indicated values:
++
+----------
+	mailnews.send_plaintext_flowed  => false
+	mailnews.wraplength             => 0
+----------
+
+4. Open a compose window and click the external editor icon.
+
+5. In the external editor window, read in the patch file and exit
+   the editor normally.
+
+Side note: it may be possible to do step 2 with
+about:config and the following settings but no one's tried yet.
+
+----------
+	mail.html_compose                       => false
+	mail.identity.default.compose_html      => false
+	mail.identity.id?.compose_html          => false
+----------
+
+There is a script in contrib/thunderbird-patch-inline which can help
+you include patches with Thunderbird in an easy way. To use it, do the
+steps above and then use the script as the external editor.
+
 
 EXAMPLES
 --------