[GSoC][PATCH 1/5 v4] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6abdad329..7af4de09b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,27 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
        return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+       const char *super_prefix = get_super_prefix();
+
+       if (prefix && super_prefix) {
+               BUG("cannot have prefix '%s' and superprefix '%s'",
+                   prefix, super_prefix);
+       } else if (prefix) {
+               struct strbuf sb = STRBUF_INIT;
+               char *displaypath = xstrdup(relative_path(path, prefix, &sb));
+               strbuf_release(&sb);
+               return displaypath;
+       } else if (super_prefix) {
+               int len = strlen(super_prefix);
+               const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+               return xstrfmt(format, super_prefix, path);
+       } else {
+               return xstrdup(path);
+       }
+}
+
 struct module_list {
        const struct cache_entry **entries;
        int alloc, nr;
@@ -339,16 +360,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
        /* Only loads from .gitmodules, no overlay with .git/config */
        gitmodules_config();
-
-       if (prefix && get_super_prefix())
-               die("BUG: cannot have prefix and superprefix");
-       else if (prefix)
-               displaypath = xstrdup(relative_path(path, prefix, &sb));
-       else if (get_super_prefix()) {
-               strbuf_addf(&sb, "%s%s", get_super_prefix(), path);
-               displaypath = strbuf_detach(&sb, NULL);
-       } else
-               displaypath = xstrdup(path);
+       displaypath = get_submodule_displaypath(path, prefix);
 
        sub = submodule_from_path(null_sha1, path);
 
@@ -363,7 +375,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
         * Set active flag for the submodule being initialized
         */
        if (!is_submodule_active(the_repository, path)) {
-               strbuf_reset(&sb);
                strbuf_addf(&sb, "submodule.%s.active", sub->name);
                git_config_set_gently(sb.buf, "true");
        }
-- 
2.13.0