[PATCH 17/22] entry.c: optionally checkout newly cloned submodules

[skimo@liacs.nl]

From: Sven Verdoolaege <skimo@kotnet.org>

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 entry.c      |   23 ++++++++++++++++++++---
 submodules.c |   43 +++++++++++++++++++++++++++++++++++++++++++
 submodules.h |    1 +
 3 files changed, 64 insertions(+), 3 deletions(-)

diff --git a/entry.c b/entry.c
index 7ba2241..f3e0c59 100644
--- a/entry.c
+++ b/entry.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "blob.h"
 #include "run-command.h"
+#include "submodules.h"
 
 static void create_directories(const char *path, const struct checkout *state)
 {
@@ -82,7 +83,7 @@ static int checkout_submodule(struct cache_entry *ce, const char *path, const st
 	int argc;
 	int err;
 
-	if (!state->submodules)
+	if (!state->submodules && !is_checkedout_submodule(ce->name))
 		return 0;
 
 	argc = 0;
@@ -101,10 +102,25 @@ static int checkout_submodule(struct cache_entry *ce, const char *path, const st
 	return 0;
 }
 
+static int write_submodule(struct cache_entry *ce, char *path, const struct checkout *state)
+{
+	if (mkdir(path, 0777) < 0)
+		return error("git-checkout-index: cannot create subproject directory %s", path);
+
+	if (!state->submodules)
+		return 0;
+
+	if (attach_submodule(ce->name))
+		return -1;
+
+	return checkout_submodule(ce, path, state);
+}
+
 static int write_entry(struct cache_entry *ce, char *path, const struct checkout *state, int to_tempfile)
 {
 	int fd;
 	long wrote;
+	int err;
 
 	switch (ntohl(ce->ce_mode) & S_IFMT) {
 		char *buf, *new;
@@ -174,8 +190,9 @@ static int write_entry(struct cache_entry *ce, char *path, const struct checkout
 	case S_IFGITLINK:
 		if (to_tempfile)
 			return error("git-checkout-index: cannot create temporary subproject %s", path);
-		if (mkdir(path, 0777) < 0)
-			return error("git-checkout-index: cannot create subproject directory %s", path);
+		err = write_submodule(ce, path, state);
+		if (err)
+			return err;
 		break;
 	default:
 		return error("git-checkout-index: unknown file mode for %s", path);
diff --git a/submodules.c b/submodules.c
index 44c0f2c..325de33 100644
--- a/submodules.c
+++ b/submodules.c
@@ -209,3 +209,46 @@ int clone_submodule(const char *submodule)
 
 	return 0;
 }
+
+static const char *relativize_path(const char *path, const char *dest)
+{
+	static char relative_path[PATH_MAX];
+	int slashes;
+	const char *cp;
+	char *rp;
+
+	if (path[0] == '/')
+		return path;
+
+	for (slashes = 0, cp = strchr(dest, '/'); cp; cp = strchr(cp, '/')) {
+		++slashes;
+		while (*cp == '/')
+			++cp;
+	}
+	if (3 * slashes + strlen(path) + 1 > sizeof(relative_path))
+		die("path too long");
+
+	rp = relative_path;
+	while (slashes--) {
+		memcpy(rp, "../", 3);
+		rp += 3;
+	}
+	strcpy(rp, path);
+
+	return relative_path;
+}
+
+int attach_submodule(const char *submodule)
+{
+	struct stat st;
+	const char *submodule_dir, *dest;
+
+	submodule_dir = git_path("submodules/%s/.git", submodule);
+	if (lstat(submodule_dir, &st))
+		return error("submodule '%s' unavailable", submodule);
+
+	dest = mkpath("%s/.git", submodule);
+	submodule_dir = relativize_path(submodule_dir, dest);
+
+	return symlink(submodule_dir, dest);
+}
diff --git a/submodules.h b/submodules.h
index bf3f118..57432bb 100644
--- a/submodules.h
+++ b/submodules.h
@@ -3,5 +3,6 @@
 
 int is_checkedout_submodule(const char *path);
 int clone_submodule(const char *submodule);
+int attach_submodule(const char *submodule);
 
 #endif
-- 
1.5.2.784.g5532e