Re: [GSoC][PATCH 06/13] submodule: port submodule subcommand 'deinit' from shell to C

On Tue, Aug 1, 2017 at 3:12 AM, Stefan Beller [off-list ref] wrote:

On Mon, Jul 31, 2017 at 1:56 PM, Prathamesh Chavan [off-list ref] wrote:

quoted

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into three
functions: module_deinit(), for_each_submodule_list() and
deinit_submodule().

Mentored-by: Christian Couder [off-list ref]
Mentored-by: Stefan Beller [off-list ref]
Signed-off-by: Prathamesh Chavan <redacted>
---
In this new version, the following changes have been made:
* In the function deinit_submodule, since the test is_git_directory()
  adds an additional condition, instead is_directory() is used to check
  if "sm_path/.git" is a directory.

Thanks for writing these patches.
I wonder if (some of) these notes are best put into the code
as a comment such as

    /* NEEDSWORK: convert to is_submodule_active */

such that people reading this code later realize that checking
for a directory may not be the "correct" thing, but a thing which
was easy to express using shell.

quoted

+struct deinit_cb {
+       const char *prefix;
+       unsigned int quiet: 1;
+       unsigned int force: 1;
+       unsigned int all: 1;

The value 'all' seems to be unused, i.e. we assign it but never read it?

quoted

+};
+#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
+
+static void deinit_submodule(const struct cache_entry *list_item,
+                            void *cb_data)
+{
+       struct deinit_cb *info = cb_data;
+       const struct submodule *sub;
+       char *displaypath = NULL;
+       struct child_process cp_config = CHILD_PROCESS_INIT;
+       struct strbuf sb_config = STRBUF_INIT;
+       char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
+       mode_t mode = 0777;
+
+       sub = submodule_from_path(null_sha1, list_item->name);
+
+       if (!sub || !sub->name)
+               goto cleanup;
+
+       displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+       /* remove the submodule work tree (unless the user already did it) */
+       if (is_directory(list_item->name)) {
+               struct stat st;
+               /* protect submodules containing a .git directory */

Here may a good place to put:
  /* NEEDSWORK: automatically call absorbgitdirs before warning/die. */
(It was not in the shell version, so feel free to ignore)

quoted

+               if (!info->force) {
+                       struct child_process cp_rm = CHILD_PROCESS_INIT;
+                       cp_rm.git_cmd = 1;
+                       argv_array_pushl(&cp_rm.args, "rm", "-qn",
+                                        list_item->name, NULL);

A bug that exists in the shell version as well as here:
What if the submodule has the name '--cached', which happens
to be a valid argument for git-rm?

The call to git-rm would die claiming that the <file> is missing,
as the file name was miss-interpreted as another flag.

To solve this problem we would insert a '--' after the options,
before the file name to state that the last argument is a <file>.

Not sure if we want to fix the bug while we're here or if we rather
want to add

    /* NEEDSWORK: add '--' to confirm <file> argument */

IMO, I would first port the subcommand, and add an additional comment
for pointing the bug out. And then later, we may have a bug-fix patch in this
series of patch itself for tackling this bug out.

Thanks,
Prathamesh Chavan