Merge branch 'jl/submodule-rm'

"git rm submodule" cannot blindly remove a submodule directory as
its working tree may have local changes, and worse yet, it may even
have its repository embedded in it.  Teach it some special cases
where it is safe to remove a submodule, specifically, when there is
no local changes in the submodule working tree, and its repository
is not embedded in its working tree but is elsewhere and uses the
gitfile mechanism to point at it.

* jl/submodule-rm:
  submodule: teach rm to remove submodules unless they contain a git directory

1 files changed, 110 insertions, 15 deletions

diff --git a/builtin/rm.c b/builtin/rm.c
index b384c4c..2aea3b5 100644
--- a/builtin/rm.c
+++ b/builtin/rm.c
@@ -9,6 +9,7 @@
 #include "cache-tree.h"
 #include "tree-walk.h"
 #include "parse-options.h"
+#include "submodule.h"
 
 static const char * const builtin_rm_usage[] = {
 	N_("git rm [options] [--] <file>..."),
@@ -17,9 +18,58 @@ static const char * const builtin_rm_usage[] = {
 
 static struct {
 	int nr, alloc;
-	const char **name;
+	struct {
+		const char *name;
+		char is_submodule;
+	} *entry;
 } list;
 
+static int get_ours_cache_pos(const char *path, int pos)
+{
+	int i = -pos - 1;
+
+	while ((i < active_nr) && !strcmp(active_cache[i]->name, path)) {
+		if (ce_stage(active_cache[i]) == 2)
+			return i;
+		i++;
+	}
+	return -1;
+}
+
+static int check_submodules_use_gitfiles(void)
+{
+	int i;
+	int errs = 0;
+
+	for (i = 0; i < list.nr; i++) {
+		const char *name = list.entry[i].name;
+		int pos;
+		struct cache_entry *ce;
+		struct stat st;
+
+		pos = cache_name_pos(name, strlen(name));
+		if (pos < 0) {
+			pos = get_ours_cache_pos(name, pos);
+			if (pos < 0)
+				continue;
+		}
+		ce = active_cache[pos];
+
+		if (!S_ISGITLINK(ce->ce_mode) ||
+		    (lstat(ce->name, &st) < 0) ||
+		    is_empty_dir(name))
+			continue;
+
+		if (!submodule_uses_gitfile(name))
+			errs = error(_("submodule '%s' (or one of its nested "
+				     "submodules) uses a .git directory\n"
+				     "(use 'rm -rf' if you really want to remove "
+				     "it including all of its history)"), name);
+	}
+
+	return errs;
+}
+
 static int check_local_mod(unsigned char *head, int index_only)
 {
 	/*
@@ -37,15 +87,26 @@ static int check_local_mod(unsigned char *head, int index_only)
 		struct stat st;
 		int pos;
 		struct cache_entry *ce;
-		const char *name = list.name[i];
+		const char *name = list.entry[i].name;
 		unsigned char sha1[20];
 		unsigned mode;
 		int local_changes = 0;
 		int staged_changes = 0;
 
 		pos = cache_name_pos(name, strlen(name));
-		if (pos < 0)
-			continue; /* removing unmerged entry */
+		if (pos < 0) {
+			/*
+			 * Skip unmerged entries except for populated submodules
+			 * that could lose history when removed.
+			 */
+			pos = get_ours_cache_pos(name, pos);
+			if (pos < 0)
+				continue;
+
+			if (!S_ISGITLINK(active_cache[pos]->ce_mode) ||
+			    is_empty_dir(name))
+				continue;
+		}
 		ce = active_cache[pos];
 
 		if (lstat(ce->name, &st) < 0) {
@@ -58,9 +119,10 @@ static int check_local_mod(unsigned char *head, int index_only)
 			/* if a file was removed and it is now a
 			 * directory, that is the same as ENOENT as
 			 * far as git is concerned; we do not track
-			 * directories.
+			 * directories unless they are submodules.
 			 */
-			continue;
+			if (!S_ISGITLINK(ce->ce_mode))
+				continue;
 		}
 
 		/*
@@ -80,8 +142,11 @@ static int check_local_mod(unsigned char *head, int index_only)
 
 		/*
 		 * Is the index different from the file in the work tree?
+		 * If it's a submodule, is its work tree modified?
 		 */
-		if (ce_match_stat(ce, &st, 0))
+		if (ce_match_stat(ce, &st, 0) ||
+		    (S_ISGITLINK(ce->ce_mode) &&
+		     !ok_to_remove_submodule(ce->name)))
 			local_changes = 1;
 
 		/*
@@ -115,10 +180,18 @@ static int check_local_mod(unsigned char *head, int index_only)
 				errs = error(_("'%s' has changes staged in the index\n"
 					     "(use --cached to keep the file, "
 					     "or -f to force removal)"), name);
-			if (local_changes)
-				errs = error(_("'%s' has local modifications\n"
-					     "(use --cached to keep the file, "
-					     "or -f to force removal)"), name);
+			if (local_changes) {
+				if (S_ISGITLINK(ce->ce_mode) &&
+				    !submodule_uses_gitfile(name)) {
+					errs = error(_("submodule '%s' (or one of its nested "
+						     "submodules) uses a .git directory\n"
+						     "(use 'rm -rf' if you really want to remove "
+						     "it including all of its history)"), name);
+				} else
+					errs = error(_("'%s' has local modifications\n"
+						     "(use --cached to keep the file, "
+						     "or -f to force removal)"), name);
+			}
 		}
 	}
 	return errs;
@@ -173,8 +246,9 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 		struct cache_entry *ce = active_cache[i];
 		if (!match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen))
 			continue;
-		ALLOC_GROW(list.name, list.nr + 1, list.alloc);
-		list.name[list.nr++] = ce->name;
+		ALLOC_GROW(list.entry, list.nr + 1, list.alloc);
+		list.entry[list.nr].name = ce->name;
+		list.entry[list.nr++].is_submodule = S_ISGITLINK(ce->ce_mode);
 	}
 
 	if (pathspec) {
@@ -215,6 +289,9 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 			hashclr(sha1);
 		if (check_local_mod(sha1, index_only))
 			exit(1);
+	} else if (!index_only) {
+		if (check_submodules_use_gitfiles())
+			exit(1);
 	}
 
 	/*
@@ -222,7 +299,7 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 	 * the index unless all of them succeed.
 	 */
 	for (i = 0; i < list.nr; i++) {
-		const char *path = list.name[i];
+		const char *path = list.entry[i].name;
 		if (!quiet)
 			printf("rm '%s'\n", path);
 
@@ -244,7 +321,25 @@ int cmd_rm(int argc, const char **argv, const char *prefix)
 	if (!index_only) {
 		int removed = 0;
 		for (i = 0; i < list.nr; i++) {
-			const char *path = list.name[i];
+			const char *path = list.entry[i].name;
+			if (list.entry[i].is_submodule) {
+				if (is_empty_dir(path)) {
+					if (!rmdir(path)) {
+						removed = 1;
+						continue;
+					}
+				} else {
+					struct strbuf buf = STRBUF_INIT;
+					strbuf_addstr(&buf, path);
+					if (!remove_dir_recursively(&buf, 0)) {
+						removed = 1;
+						strbuf_release(&buf);
+						continue;
+					}
+					strbuf_release(&buf);
+					/* Fallthrough and let remove_path() fail. */
+				}
+			}
 			if (!remove_path(path)) {
 				removed = 1;
 				continue;