Re: [PATCH v10 0/9] submodule inline diff format

Jacob Keller [off-list ref] writes:

So we should support the gitlink to a repository stored at <path>
without stuff inside the .git/modules, and we should support submodule
gitlinks with a proper .gitmodules setup. I don't think we should
die() but we should error properly so I will introduce a _gently()
variant of these functions, and die properly in the regular flow.

Because "git diff [--cached] [<tree-ish>]" in the top-level is
driven by a gitlink in the index, immediately after adding a new
submodule to the index but before describing it in .gitmodules you
might not have a name (and you know in that case the path will
become the name when adding it to .gitmodules).  Also a gitlink in
the index may correspond to a submodule the user of the top-level is
not interested in, so there may not be anything in .git/modules/
that corresponds to it.  In these cases, I suspect that you do not
want to die, but you can just tell the user "I do not have enough
information to tell you a useful story yet".

On Thu, Aug 25, 2016 at 3:38 PM, Junio C Hamano [off-list ref] wrote:

Jacob Keller [off-list ref] writes:

quoted

So we should support the gitlink to a repository stored at <path>
without stuff inside the .git/modules, and we should support submodule
gitlinks with a proper .gitmodules setup. I don't think we should
die() but we should error properly so I will introduce a _gently()
variant of these functions, and die properly in the regular flow.

Because "git diff [--cached] [<tree-ish>]" in the top-level is
driven by a gitlink in the index, immediately after adding a new
submodule to the index but before describing it in .gitmodules you
might not have a name (and you know in that case the path will
become the name when adding it to .gitmodules).  Also a gitlink in
the index may correspond to a submodule the user of the top-level is
not interested in, so there may not be anything in .git/modules/
that corresponds to it.  In these cases, I suspect that you do not
want to die, but you can just tell the user "I do not have enough
information to tell you a useful story yet".

Right. submodule_from_path() fails to find a config. I don't think
die() is right here, because there is no easy way to make this into a
gently() variant.... I can still do it if we think a die() is
worthwhile otherwise for the other callers of do_submodule_path...

However, I think the safest thing is to just:

a) read_gitfile on <path>/.git
b) if read_gitfile succeeds, use it's contents, otherwise use
<path>/.git for next steps
c) check if the resulting file is a git directory, we're fine.. we
found a gitdir, so stop.
d) otherwise,  empty the buffer, then lookup submodules
e) when submodules lookup succeeds.. see if we found a name. If so, use that.
f) if we didn't just exit with an empty buffer.

That empty buffer *should* trigger  revision error codes since it
won't point to any valid path and it also triggers the regular error
code in add_submodule_odb so it handles that with showing not
initizlied.

This method is less work then re-implementing a _gently() variant for
all of these functions.

Stefan, does this make sense and seem reasonable?

If we just die when submodule_from_path fails I think it's bad for the
submodule=* formats beside short. I don't know if it causes problems
for revision code or not... I think falling back to resetting the
buffer as our way of indicating error is reasonable enough...

Thanks,
Jake

On Thu, Aug 25, 2016 at 3:46 PM, Jacob Keller [off-list ref] wrote:

On Thu, Aug 25, 2016 at 3:38 PM, Junio C Hamano [off-list ref] wrote:

quoted

Jacob Keller [off-list ref] writes:

quoted

So we should support the gitlink to a repository stored at <path>
without stuff inside the .git/modules, and we should support submodule
gitlinks with a proper .gitmodules setup. I don't think we should
die() but we should error properly so I will introduce a _gently()
variant of these functions, and die properly in the regular flow.

Because "git diff [--cached] [<tree-ish>]" in the top-level is
driven by a gitlink in the index, immediately after adding a new
submodule to the index but before describing it in .gitmodules you
might not have a name (and you know in that case the path will
become the name when adding it to .gitmodules).  Also a gitlink in
the index may correspond to a submodule the user of the top-level is
not interested in, so there may not be anything in .git/modules/
that corresponds to it.  In these cases, I suspect that you do not
want to die, but you can just tell the user "I do not have enough
information to tell you a useful story yet".

Right. submodule_from_path() fails to find a config. I don't think
die() is right here, because there is no easy way to make this into a
gently() variant.... I can still do it if we think a die() is
worthwhile otherwise for the other callers of do_submodule_path...

However, I think the safest thing is to just:

a) read_gitfile on <path>/.git
b) if read_gitfile succeeds, use it's contents, otherwise use
<path>/.git for next steps
c) check if the resulting file is a git directory, we're fine.. we
found a gitdir, so stop.
d) otherwise,  empty the buffer, then lookup submodules
e) when submodules lookup succeeds.. see if we found a name. If so, use that.

When the submodules lookup succeeds, we can assert the name exists.
There is currently only one way the lookup is populated, and that is
lookup_or_create_by_name in submodule-config.c:182, which fills in
the name all the time.

f) if we didn't just exit with an empty buffer.

That empty buffer *should* trigger  revision error codes since it
won't point to any valid path and it also triggers the regular error
code in add_submodule_odb so it handles that with showing not
initizlied.

This method is less work then re-implementing a _gently() variant for
all of these functions.

Stefan, does this make sense and seem reasonable?

Sounds reasonable to me.

Thanks for working on this!
Stefan

On Fri, 2016-08-26 at 10:35 -0700, Stefan Beller wrote:

quoted

a) read_gitfile on <path>/.git
b) if read_gitfile succeeds, use it's contents, otherwise use
<path>/.git for next steps
c) check if the resulting file is a git directory, we're fine.. we
found a gitdir, so stop.
d) otherwise,  empty the buffer, then lookup submodules
e) when submodules lookup succeeds.. see if we found a name. If so,
use that.

When the submodules lookup succeeds, we can assert the name exists.
There is currently only one way the lookup is populated, and that is
lookup_or_create_by_name in submodule-config.c:182, which fills in
the name all the time.

Yes, that was how I was trying to word it, and that's what I've done in
code.

quoted

f) if we didn't just exit with an empty buffer.

That empty buffer *should* trigger  revision error codes since it
won't point to any valid path and it also triggers the regular
error
code in add_submodule_odb so it handles that with showing not
initizlied.

This method is less work then re-implementing a _gently() variant
for
all of these functions.

Stefan, does this make sense and seem reasonable?

Sounds reasonable to me.

Thanks for working on this!
Stefan

Thanks for review!

Regards,
Jake