[GSoC][PATCH v4 1/4] 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 | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 818fe74f0..e25854371 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,28 @@ 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;
@@ -335,15 +357,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
        struct strbuf sb = STRBUF_INIT;
        char *upd = NULL, *url = NULL, *displaypath;
 
-       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_oid, path);
 
@@ -358,9 +372,9 @@ 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");
+               strbuf_reset(&sb);
        }
 
        /*
@@ -368,7 +382,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
         * To look up the url in .git/config, we must not fall back to
         * .gitmodules, so look it up directly.
         */
-       strbuf_reset(&sb);
        strbuf_addf(&sb, "submodule.%s.url", sub->name);
        if (git_config_get_string(sb.buf, &url)) {
                if (!sub->url)
@@ -405,9 +418,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
                                _("Submodule '%s' (%s) registered for path 
'%s'\n"),
                                sub->name, url, displaypath);
        }
+       strbuf_reset(&sb);
 
        /* Copy "update" setting when it is not set yet */
-       strbuf_reset(&sb);
        strbuf_addf(&sb, "submodule.%s.update", sub->name);
        if (git_config_get_string(sb.buf, &upd) &&
            sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.13.0