[PATCH 04/25] remote: move relative_url()

["Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>]

From: Derrick Stolee <derrickstolee@github.com>

This method was initially written in 63e95beb0 (submodule: port
resolve_relative_url from shell to C, 2016-05-15). As we will need
similar functionality in the bundle URI feature, extract this to be
available in remote.h.

The code is exactly the same. The prototype is different only in
whitespace. The documentation comment only adds explicit instructions on
what happens when supplying two absolute URLs.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
---
 builtin/submodule--helper.c | 119 ------------------------------------
 remote.c                    |  96 +++++++++++++++++++++++++++++
 remote.h                    |  30 +++++++++
 3 files changed, 126 insertions(+), 119 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index c17dde4170f..506ebd8e6bc 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -70,125 +70,6 @@ static int print_default_remote(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
-/*
- * Returns 1 if it was the last chop before ':'.
- */
-static int chop_last_dir(char **remoteurl, int is_relative)
-{
-	char *rfind = find_last_dir_sep(*remoteurl);
-	if (rfind) {
-		*rfind = '\0';
-		return 0;
-	}
-
-	rfind = strrchr(*remoteurl, ':');
-	if (rfind) {
-		*rfind = '\0';
-		return 1;
-	}
-
-	if (is_relative || !strcmp(".", *remoteurl))
-		die(_("cannot strip one component off url '%s'"),
-			*remoteurl);
-
-	free(*remoteurl);
-	*remoteurl = xstrdup(".");
-	return 0;
-}
-
-/*
- * The `url` argument is the URL that navigates to the submodule origin
- * repo. When relative, this URL is relative to the superproject origin
- * URL repo. The `up_path` argument, if specified, is the relative
- * path that navigates from the submodule working tree to the superproject
- * working tree. Returns the origin URL of the submodule.
- *
- * Return either an absolute URL or filesystem path (if the superproject
- * origin URL is an absolute URL or filesystem path, respectively) or a
- * relative file system path (if the superproject origin URL is a relative
- * file system path).
- *
- * When the output is a relative file system path, the path is either
- * relative to the submodule working tree, if up_path is specified, or to
- * the superproject working tree otherwise.
- *
- * NEEDSWORK: This works incorrectly on the domain and protocol part.
- * remote_url      url              outcome          expectation
- * http://a.com/b  ../c             http://a.com/c   as is
- * http://a.com/b/ ../c             http://a.com/c   same as previous line, but
- *                                                   ignore trailing slash in url
- * http://a.com/b  ../../c          http://c         error out
- * http://a.com/b  ../../../c       http:/c          error out
- * http://a.com/b  ../../../../c    http:c           error out
- * http://a.com/b  ../../../../../c    .:c           error out
- * NEEDSWORK: Given how chop_last_dir() works, this function is broken
- * when a local part has a colon in its path component, too.
- */
-static char *relative_url(const char *remote_url,
-				const char *url,
-				const char *up_path)
-{
-	int is_relative = 0;
-	int colonsep = 0;
-	char *out;
-	char *remoteurl = xstrdup(remote_url);
-	struct strbuf sb = STRBUF_INIT;
-	size_t len = strlen(remoteurl);
-
-	if (is_dir_sep(remoteurl[len-1]))
-		remoteurl[len-1] = '\0';
-
-	if (!url_is_local_not_ssh(remoteurl) || is_absolute_path(remoteurl))
-		is_relative = 0;
-	else {
-		is_relative = 1;
-		/*
-		 * Prepend a './' to ensure all relative
-		 * remoteurls start with './' or '../'
-		 */
-		if (!starts_with_dot_slash(remoteurl) &&
-		    !starts_with_dot_dot_slash(remoteurl)) {
-			strbuf_reset(&sb);
-			strbuf_addf(&sb, "./%s", remoteurl);
-			free(remoteurl);
-			remoteurl = strbuf_detach(&sb, NULL);
-		}
-	}
-	/*
-	 * When the url starts with '../', remove that and the
-	 * last directory in remoteurl.
-	 */
-	while (url) {
-		if (starts_with_dot_dot_slash(url)) {
-			url += 3;
-			colonsep |= chop_last_dir(&remoteurl, is_relative);
-		} else if (starts_with_dot_slash(url))
-			url += 2;
-		else
-			break;
-	}
-	strbuf_reset(&sb);
-	strbuf_addf(&sb, "%s%s%s", remoteurl, colonsep ? ":" : "/", url);
-	if (ends_with(url, "/"))
-		strbuf_setlen(&sb, sb.len - 1);
-	free(remoteurl);
-
-	if (starts_with_dot_slash(sb.buf))
-		out = xstrdup(sb.buf + 2);
-	else
-		out = xstrdup(sb.buf);
-
-	if (!up_path || !is_relative) {
-		strbuf_release(&sb);
-		return out;
-	}
-
-	strbuf_reset(&sb);
-	strbuf_addf(&sb, "%s%s", up_path, out);
-	free(out);
-	return strbuf_detach(&sb, NULL);
-}
-
 static char *resolve_relative_url(const char *rel_url, const char *up_path, int quiet)
 {
 	char *remoteurl, *resolved_url;
diff --git a/remote.c b/remote.c
index c97c626eaa8..c4a56749e85 100644
--- a/remote.c
+++ b/remote.c
@@ -14,6 +14,7 @@
 #include "strvec.h"
 #include "commit-reach.h"
 #include "advice.h"
+#include "connect.h"
 
 enum map_direction { FROM_SRC, FROM_DST };
 
@@ -2727,3 +2728,98 @@ void remote_state_clear(struct remote_state *remote_state)
 	hashmap_clear_and_free(&remote_state->remotes_hash, struct remote, ent);
 	hashmap_clear_and_free(&remote_state->branches_hash, struct remote, ent);
 }
+
+/*
+ * Returns 1 if it was the last chop before ':'.
+ */
+static int chop_last_dir(char **remoteurl, int is_relative)
+{
+	char *rfind = find_last_dir_sep(*remoteurl);
+	if (rfind) {
+		*rfind = '\0';
+		return 0;
+	}
+
+	rfind = strrchr(*remoteurl, ':');
+	if (rfind) {
+		*rfind = '\0';
+		return 1;
+	}
+
+	if (is_relative || !strcmp(".", *remoteurl))
+		die(_("cannot strip one component off url '%s'"),
+			*remoteurl);
+
+	free(*remoteurl);
+	*remoteurl = xstrdup(".");
+	return 0;
+}
+
+/*
+ * NEEDSWORK: Given how chop_last_dir() works, this function is broken
+ * when a local part has a colon in its path component, too.
+ */
+char *relative_url(const char *remote_url,
+		   const char *url,
+		   const char *up_path)
+{
+	int is_relative = 0;
+	int colonsep = 0;
+	char *out;
+	char *remoteurl = xstrdup(remote_url);
+	struct strbuf sb = STRBUF_INIT;
+	size_t len = strlen(remoteurl);
+
+	if (is_dir_sep(remoteurl[len-1]))
+		remoteurl[len-1] = '\0';
+
+	if (!url_is_local_not_ssh(remoteurl) || is_absolute_path(remoteurl))
+		is_relative = 0;
+	else {
+		is_relative = 1;
+		/*
+		 * Prepend a './' to ensure all relative
+		 * remoteurls start with './' or '../'
+		 */
+		if (!starts_with_dot_slash(remoteurl) &&
+		    !starts_with_dot_dot_slash(remoteurl)) {
+			strbuf_reset(&sb);
+			strbuf_addf(&sb, "./%s", remoteurl);
+			free(remoteurl);
+			remoteurl = strbuf_detach(&sb, NULL);
+		}
+	}
+	/*
+	 * When the url starts with '../', remove that and the
+	 * last directory in remoteurl.
+	 */
+	while (url) {
+		if (starts_with_dot_dot_slash(url)) {
+			url += 3;
+			colonsep |= chop_last_dir(&remoteurl, is_relative);
+		} else if (starts_with_dot_slash(url))
+			url += 2;
+		else
+			break;
+	}
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s%s%s", remoteurl, colonsep ? ":" : "/", url);
+	if (ends_with(url, "/"))
+		strbuf_setlen(&sb, sb.len - 1);
+	free(remoteurl);
+
+	if (starts_with_dot_slash(sb.buf))
+		out = xstrdup(sb.buf + 2);
+	else
+		out = xstrdup(sb.buf);
+
+	if (!up_path || !is_relative) {
+		strbuf_release(&sb);
+		return out;
+	}
+
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "%s%s", up_path, out);
+	free(out);
+	return strbuf_detach(&sb, NULL);
+}
diff --git a/remote.h b/remote.h
index 4a1209ae2c8..91c7f187863 100644
--- a/remote.h
+++ b/remote.h
@@ -409,4 +409,34 @@ int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
 int is_empty_cas(const struct push_cas_option *);
 void apply_push_cas(struct push_cas_option *, struct remote *, struct ref *);
 
+/*
+ * The `url` argument is the URL that navigates to the submodule origin
+ * repo. When relative, this URL is relative to the superproject origin
+ * URL repo. The `up_path` argument, if specified, is the relative
+ * path that navigates from the submodule working tree to the superproject
+ * working tree. Returns the origin URL of the submodule.
+ *
+ * Return either an absolute URL or filesystem path (if the superproject
+ * origin URL is an absolute URL or filesystem path, respectively) or a
+ * relative file system path (if the superproject origin URL is a relative
+ * file system path).
+ *
+ * When the output is a relative file system path, the path is either
+ * relative to the submodule working tree, if up_path is specified, or to
+ * the superproject working tree otherwise.
+ *
+ * NEEDSWORK: This works incorrectly on the domain and protocol part.
+ * remote_url      url              outcome          expectation
+ * http://a.com/b  ../c             http://a.com/c   as is
+ * http://a.com/b/ ../c             http://a.com/c   same as previous line, but
+ *                                                   ignore trailing slash in url
+ * http://a.com/b  ../../c          http://c         error out
+ * http://a.com/b  ../../../c       http:/c          error out
+ * http://a.com/b  ../../../../c    http:c           error out
+ * http://a.com/b  ../../../../../c    .:c           error out
+ */
+char *relative_url(const char *remote_url,
+		   const char *url,
+		   const char *up_path);
+
 #endif
-- 
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