Subject: Re: [PATCH] Teach git-commit about commit message templates.

From: Steven Grimm <[email-masked]>
Date: Mon, 23 Jul 2007 18:56:09 +0800

Johannes Schindelin wrote:
> Ah, I missed that.  But IIRC your patch does not wrap that logic behind 
> test ! -z "$templatefile", right?  So this is my modified suggestion:
>
> test ! -z "$templatefile" && {
> 	grep -vie '^Signed-off-by:' < "$GIT_DIR"/COMMIT_MSG" > "$GIT_DIR"/tmp1
> 	grep -ve '^#' < "$templatefile" > "$GIT_DIR"/tmp1
> 	trap 'rm "$GIT_DIR"/tmp[12]' 0
> 	cmp "$GIT_DIR"/tmp[12] &&
> 	die "Unchanged message; will not commit"
> }
>   

So you are suggesting I do this in addition to the existing git-commit 
stripping of Signed-off-by: lines? I can certainly do that, but I didn't 
want to make two passes over the commit message doing exactly the same 
stripping.

Hmm, maybe I should outline my understanding of the current (unpatched) 
behavior and what I want it to do. Currently:

* Strip off all comment lines (happens when COMMIT_MSG is created)
* Strip off all Signed-off-by: lines
* Trim whitespace
* If the result has no content (`wc -l` == 0), abort.

With the patch, my intent was:

* Strip off all comment lines
* Strip off all Signed-off-by: lines
* Trim whitespace
* If the result has no content (! -s file), abort.
* If a template file was specified:
   * Strip off all comment and Signed-off-by: lines from the template
   * Trim whitespace from the template
   * If the resulting trimmed template is the same as the trimmed commit 
message, abort.

So I guess before getting to the specifics of the code, I'll ask: does 
the above make sense as a design? I wanted to preserve the existing 
behavior in the absence of a template.

Since the existing code is already stripping Signed-off-by: lines to 
test for a zero-length commit message, I figured I should reuse that 
work. However, it's no big deal to do it twice if people feel that 
results in more readable code -- certainly no human will ever notice the 
time it takes to re-grep the commit message.

-Steve