Allow custom "comment char"

Some users do want to write a line that begin with a pound sign, #,
in their commit log message.  Many tracking system recognise
a token of #<bugid> form, for example.

The support we offer these use cases is not very friendly to the end
users.  They have a choice between

 - Don't do it.  Avoid such a line by rewrapping or indenting; and

 - Use --cleanup=whitespace but remove all the hint lines we add.

Give them a way to set a custom comment char, e.g.

    $ git -c core.commentchar="%" commit

so that they do not have to do either of the two workarounds.

[jc: although I started the topic, all the tests and documentation
updates, many of the call sites of the new strbuf_add_commented_*()
functions, and the change to git-submodule.sh scripted Porcelain are
from Ralf.]

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d5809e0e8c..e99b9f234e 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -528,6 +528,12 @@ core.editor::
 	variable when it is set, and the environment variable
 	`GIT_EDITOR` is not set.  See linkgit:git-var[1].
 
+core.commentchar::
+	Commands such as `commit` and `tag` that lets you edit
+	messages consider a line that begins with this character
+	commented, and removes them after the editor returns
+	(default '#').
+
 sequence.editor::
 	Text editor used by `git rebase -i` for editing the rebase insn file.
 	The value is meant to be interpreted by the shell when it is used.