Re: [PATCH 1/4] git-prompt.sh: add submodule indicator

> Benjamin Fuchs <email@benjaminfuchs.de> writes:
>
>> I expirienced that working with submodules can be confusing. This indicator
>> will make you notice very easy when you switch into a submodule.
> I am not quite sure what the above wants to say.  If you work on two
> projects, A and B, then having something that quickly reminds you
> which one you are in is beneficial and people often do so by having
> the current directory name in the prompt.
>
> The log message needs to explain why working on a submodule C of a
> project A is any more special, i.e. why are the existing ways the
> users are using to remind them between A and B cannot be used for C.

>
>> diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
>> index 97eacd7..4c82e7f 100644
>> --- a/contrib/completion/git-prompt.sh
>> +++ b/contrib/completion/git-prompt.sh
>> @@ -93,6 +93,10 @@
>>   # directory is set up to be ignored by git, then set
>>   # GIT_PS1_HIDE_IF_PWD_IGNORED to a nonempty value. Override this on the
>>   # repository level by setting bash.hideIfPwdIgnored to "false".
>> +#
>> +# If you would like __git_ps1 to indicate that you are in a submodule,
>> +# set GIT_PS1_SHOWSUBMODULE. In this case a "sub:" will be added before
>> +# the branch name.
>>   
>>   # check whether printf supports -v
>>   __git_printf_supports_v=
>> @@ -284,6 +288,32 @@ __git_eread ()
>>   	test -r "$f" && read "$@" <"$f"
>>   }
>>   
>> +# __git_is_submodule
>> +# Based on:
>> +# http://stackoverflow.com/questions/7359204/git-command-line-know-if-in-submodule
>> +__git_is_submodule ()
> It seems like this function is checking if you are "IN" submodule,
> not "IS" submodule.  A misnamed function?

>> +{
>> +	local git_dir parent_git module_name path
>> +	# Find the root of this git repo, then check if its parent dir is also a repo
>> +	git_dir="$(git rev-parse --show-toplevel)"
>> +	module_name="$(basename "$git_dir")"
> This does not give "module_name" in the sense the word is used in
> the submodule subsystem.  If this variable is useful, call that
> with "path" in its name (I do not think it alone is useful at all).

>
>> +	parent_git="$(cd "$git_dir/.." && git rev-parse --show-toplevel 2> /dev/null)"
>> +	if [[ -n $parent_git ]]; then
>> +		# List all the submodule paths for the parent repo
>> +		while read path
>> +		do
>> +			if [[ "$path" != "$module_name" ]]; then continue; fi
>> +			if [[ -d "$git_dir/../$path" ]];    then return 0; fi
>> +		done < <(cd $parent_git && git submodule --quiet foreach 'echo $path' 2> /dev/null)
> Instead of doing this "loop over submodules and just get true or
> false", it may make a lot more sense to find the module name and
> report that.  That would allow you to have the actual submodule
> name, not a generic "sub:" which does not help the users to tell
> which one of 47 submodules they have in their top-level project
> they are currently in.
>
> If your projects are layed out like so
>
> 	/home/bf/projects/A/
> 	/home/bf/projects/A/lib/B/ -- submodule
> 	/home/bf/projects/A/Doc/ -- another submodule
> 	/home/bf/projects/A/Doc/technical -- a subdirectory of Doc submodule
>
> and you are in /home/bf/projects/A/Doc/technical/ subdirectory, your
> $git_dir variable (which is grossly misnamed, too; call it "top"
> perhaps?) would be "/home/bf/projects/A/Doc" and then your
> $parent_git variable (again, that is misnamed; call it
> "parent_top"?) would be "/home/bf/projects/A".  The submodule path
> to the submodule you are currently in is "Doc" (you learn it as the
> difference between these two).
>
> You can ask the top-level project the name of the submodule that is
> currently at "Doc" with "submodule--helper name".  Unless the project
> has moved it since it first added the submodule, the module name may
> also be "Doc", but if it were moved, it may be different.
>
> And that "module name" is a more useful thing than a hardcoded
> string "sub:" to use in the prompt, I would think.