hvoigt · phord · Jul 1, 2015 · Jul 1, 2015 · Jul 1, 2015
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
@@ -608,6 +608,10 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				flags |= GET_SHA1_QUIETLY;
 				continue;
 			}
+			if (!strcmp(arg, "--recurse-submodules")) {
+				flags |= GET_SHA1_FOLLOW_GITLINKS;
+				continue;
+			}
 			if (!strcmp(arg, "--short") ||
 			    starts_with(arg, "--short=")) {
 				filter &= ~(DO_FLAGS|DO_NOREV);

diff --git a/cache.h b/cache.h
@@ -985,6 +985,7 @@ struct object_context {
 #define GET_SHA1_TREEISH          020
 #define GET_SHA1_BLOB             040
 #define GET_SHA1_FOLLOW_SYMLINKS 0100
+#define GET_SHA1_FOLLOW_GITLINKS 0200
 #define GET_SHA1_ONLY_TO_DIE    04000
 
 extern int get_sha1(const char *str, unsigned char *sha1);

diff --git a/sha1_name.c b/sha1_name.c
@@ -1437,6 +1437,9 @@ static int get_sha1_with_context_1(const char *name,
 				ret = get_tree_entry_follow_symlinks(tree_sha1,
 					filename, sha1, &oc->symlink_path,
 					&oc->mode);
+			} else if (flags & GET_SHA1_FOLLOW_GITLINKS) {
+				ret = get_tree_entry_recurse_submodules(tree_sha1,
+					filename, sha1, &oc->mode);
 			} else {
 				ret = get_tree_entry(tree_sha1, filename,
 						     sha1, &oc->mode);

diff --git a/submodule.c b/submodule.c
@@ -159,6 +159,47 @@ static int add_submodule_odb(const char *path)
 	return ret;
 }
 
+/* Add the submodule's database to alt_odb_list if it exists. Optionally
+ * lookup the commit at sha1 to determine reachability.
+ */
+int add_submodule_odb_from_tree(const char *path, int len, const unsigned char *toplevel_sha1, const unsigned char *sha1)
+{
+	int retval=0;
+	struct strbuf sm_name = STRBUF_INIT;
+
+	strbuf_addstr(&sm_name, path);
+
+	if (!len)
+		return ODB_SUBMODULE_BADPATH;
+
+	if (toplevel_sha1)
+	{
+		struct strbuf gitdir = STRBUF_INIT;
+		const struct submodule *sm;
+		if (path[len-1]=='/') --len;
+		strbuf_add(&gitdir, path, len);
+
+		sm=submodule_from_path(toplevel_sha1, gitdir.buf);
+		if (!sm)
+			retval = ODB_SUBMODULE_MISSING;
+		else {
+			strbuf_reset(&sm_name);
+			strbuf_addstr(&sm_name, sm->name);
+		}
+	}
+
+	if (retval)
+		(void)0;/* all done */
+	else if (add_submodule_odb(sm_name.buf))
+		retval = ODB_SUBMODULE_MISSING;
+	else if ( sha1 && !lookup_commit_reference(sha1))
+		retval = ODB_SUBMODULE_MISSING_REF;
+	else
+		retval = ODB_SUBMODULE_OK;
+
+	return retval;
+}
+
 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 					     const char *path)
 {

diff --git a/submodule.h b/submodule.h
@@ -13,6 +13,13 @@ enum {
 	RECURSE_SUBMODULES_ON = 2
 };
 
+enum {
+	ODB_SUBMODULE_MISSING_REF = -1,
+	ODB_SUBMODULE_OK = 0,
+	ODB_SUBMODULE_MISSING = 1,
+	ODB_SUBMODULE_BADPATH = 2,
+};
+
 int is_staging_gitmodules_ok(void);
 int update_path_in_gitmodules(const char *oldpath, const char *newpath);
 int remove_path_from_gitmodules(const char *path);
@@ -41,5 +48,6 @@ int find_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_nam
 		struct string_list *needs_pushing);
 int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name);
 void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir);
+int add_submodule_odb_from_tree(const char *path, int len, const unsigned char *toplevel_sha1, const unsigned char *sha1);
 
 #endif
diff --git a/t/t6102-rev-parse--recurse-submodules.sh b/t/t6102-rev-parse--recurse-submodules.sh
@@ -0,0 +1,188 @@
+#!/bin/sh
+#
+
+test_description='Native support for rev-parse of objects in submodules
+
+This test verifies that rev-parse understands how to parse names of objects
+belonging to submodules of the current project.
+'
+
+. ./test-lib.sh
+
+
+test_expect_success 'setup a submodule tree' '
+	echo file > file &&
+	git add file &&
+	test_tick &&
+	git commit -m upstream &&
+	git clone . super &&
+	git clone super submodule &&
+	(
+		cd super &&
+		git submodule add ../submodule submodule1 &&
+		git submodule add ../submodule submodule2 &&
+		git submodule add ../submodule sub3 &&
+		git config -f .gitmodules --rename-section \
+			submodule.submodule1 submodule.foo1 &&
+		git config -f .gitmodules --rename-section \
+			submodule.submodule2 submodule.foo2 &&
+		git config -f .gitmodules --rename-section \
+			submodule.sub3 submodule.foo3 &&
+		git add .gitmodules &&
+		test_tick &&
+		git commit -m "submodules" &&
+		git submodule init submodule1 &&
+		git submodule init submodule2 &&
+		git submodule init sub3
+	) &&
+	(
+		cd submodule &&
+		echo different > file &&
+		git add file &&
+		test_tick &&
+		git commit -m "different"
+	) &&
+	(
+		cd super &&
+		(
+			cd sub3 &&
+			git pull
+		) &&
+		git add sub3 &&
+		test_tick &&
+		git commit -m "update sub3"
+	)
+'
+
+submodule1sha1=$(cd super/submodule1 && git rev-parse HEAD)
+submodule2sha1=$(cd super/submodule2 && git rev-parse HEAD)
+sub3sha1=$(cd super/sub3 && git rev-parse HEAD)
+
+cat > expect <<EOF
+100644 blob f73f3093ff865c514c6c51f867e35f693487d0d3	file
+160000 commit $submodule1sha1	submodule1
+160000 commit $submodule2sha1	submodule2
+160000 commit $sub3sha1	sub3
+EOF
+
+test_expect_success 'setup nested submodules' '
+	git clone submodule nested1 &&
+	git clone submodule nested2 &&
+	(
+		cd nested1 &&
+		mkdir subdir &&
+		git submodule add ../nested2 subdir/nested3 &&
+		git submodule add ../nested2 nested2 &&
+		test_tick &&
+		git commit -m "nested2 and subdir/nested3" &&
+		git submodule init nested2 &&
+		git submodule init subdir/nested3
+	) &&
+	(
+		cd super &&
+		mkdir subdir &&
+		git submodule add ../nested1 subdir/nested1 &&
+		cd subdir &&
+		test_tick &&
+		git commit -m "nested1" &&
+		git submodule update --init --recursive
+	)
+'
+
+test_expect_success 'setup partially updated nested submodules' '
+	git clone super clone2 &&
+	(
+		cd clone2 &&
+		git submodule update --init &&
+		test_must_fail git rev-parse --resolve-git-dir subdir/nested1/nested2/.git &&
+		git submodule foreach "git submodule update --init" &&
+		git rev-parse --resolve-git-dir subdir/nested1/nested2/.git &&
+		test_must_fail git rev-parse --resolve-git-dir subdir/nested1/nested2/nested3/.git
+	)
+'
+test_expect_success 'rev-parse does not recurse by default' '
+	(
+		cd super &&
+		test_must_fail git rev-parse HEAD:submodule1/file
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:submodule/file' '
+	(
+		cd super &&
+		git -C submodule1 rev-parse $(git rev-parse master:submodule1):file >expected &&
+		git rev-parse --recurse-submodules master:submodule1/file >actual &&
+		test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $sha1:submodule/file' '
+	(
+		cd super &&
+		git -C submodule1 rev-parse $(git rev-parse HEAD:submodule1):file >expected &&
+		git rev-parse --recurse-submodules $(git rev-parse HEAD):submodule1/file >actual &&
+		test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules HEAD:submodule/non-existent-file fails' '
+	(
+		cd super &&
+		test_must_fail git rev-parse --recurse-submodules HEAD:submodule1/notafile
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:subdir/submodule/file' '
+	(
+		cd super &&
+		git -C subdir/nested1 rev-parse $(git rev-parse HEAD:subdir/nested1):file >expected &&
+		git rev-parse --recurse-submodules HEAD:subdir/nested1/file >actual &&
+		test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:subdir/submodule1/submodule2/file' '
+	(
+		cd super &&
+		git -C subdir/nested1/nested2 rev-parse $(git -C subdir/nested1 rev-parse HEAD:nested2):file >expected &&
+		git rev-parse --recurse-submodules HEAD:subdir/nested1/nested2/file >actual &&
+		test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:submodule1/dir1/submodule2' '
+	(
+	cd super &&
+	git -C subdir/nested1 rev-parse HEAD:subdir/nested3 >expected &&
+	git rev-parse --recurse-submodules HEAD:subdir/nested1/subdir/nested3 >actual &&
+	test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:submodule1/dir1/submodule2/' '
+	(
+	cd super &&
+	git -C subdir/nested1 rev-parse HEAD:subdir/nested3 >expected &&
+	git rev-parse --recurse-submodules HEAD:subdir/nested1/subdir/nested3/ >actual &&
+	test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:submodule1/dir1/submodule2/file' '
+	(
+		cd super &&
+		git -C subdir/nested1/subdir/nested3 rev-parse $(git -C subdir/nested1 rev-parse HEAD:subdir/nested3):file >expected &&
+		git rev-parse --recurse-submodules HEAD:subdir/nested1/subdir/nested3/file >actual &&
+		test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:dir1/submodule1/submodule2' '
+	(
+		cd super &&
+		git -C subdir/nested1 rev-parse $(git rev-parse HEAD:subdir/nested1):nested2 >expected &&
+		git rev-parse --recurse-submodules HEAD:subdir/nested1/nested2 >actual &&
+		test_cmp expected actual
+	)
+'
+test_expect_success 'rev-parse --recurse-submodules $branch:dir1/submodule1/submodule2/file' '
+	(
+		cd super &&
+		git -C subdir/nested1/nested2 rev-parse $(git -C subdir/nested1 rev-parse HEAD:nested2):file >expected &&
+		git rev-parse --recurse-submodules HEAD:subdir/nested1/nested2/file >actual &&
+		test_cmp expected actual
+	)
+'
+
+test_done
diff --git a/tree-walk.c b/tree-walk.c
@@ -3,6 +3,7 @@
 #include "unpack-trees.h"
 #include "dir.h"
 #include "tree.h"
+#include "submodule.h"
 #include "pathspec.h"
 
 static const char *get_mode(const char *str, unsigned int *modep)
@@ -415,13 +416,26 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 	return error;
 }
 
+/* Bookmark the topmost tree for gitlink following. */
+struct bookmark {
+	const unsigned char *sha1;
+	const char *path;
+	unsigned int len;
+};
+
 struct dir_state {
 	void *tree;
 	unsigned long size;
 	unsigned char sha1[20];
 };
 
-static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
+static int get_tree_entry_1(const unsigned char *tree_sha1, const char *name,
+			    unsigned char *sha1, unsigned *mode,
+			    struct bookmark *top);
+
+static int find_tree_entry(struct tree_desc *t, const char *name,
+			   unsigned char *result, unsigned *mode,
+			   struct bookmark *top)
 {
 	int namelen = strlen(name);
 	while (t->size) {
@@ -445,18 +459,37 @@ static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char
 		}
 		if (name[entrylen] != '/')
 			continue;
-		if (!S_ISDIR(*mode))
+		if (!S_ISDIR(*mode) && (!top || !S_ISGITLINK(*mode)))
 			break;
 		if (++entrylen == namelen) {
 			hashcpy(result, sha1);
 			return 0;
 		}
-		return get_tree_entry(sha1, name + entrylen, result, mode);
+		if (top) top->len += entrylen;
+		if (S_ISGITLINK(*mode))
+		{
+			add_submodule_odb_from_tree(top->path, top->len-1, top->sha1, sha1);
+			top->sha1 = NULL;
+		}
+		return get_tree_entry_1(sha1, name + entrylen, result, mode, top);
 	}
 	return -1;
 }
 
 int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
+{
+	return get_tree_entry_1(tree_sha1, name, sha1, mode, NULL);
+}
+
+int get_tree_entry_recurse_submodules(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
+{
+	struct bookmark top = {NULL, NULL, 0};
+	return get_tree_entry_1(tree_sha1, name, sha1, mode, &top);
+}
+
+static int get_tree_entry_1(const unsigned char *tree_sha1, const char *name,
+			    unsigned char *sha1, unsigned *mode,
+			    struct bookmark *top)
 {
 	int retval;
 	void *tree;
@@ -473,12 +506,19 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
 		return 0;
 	}
 
+	if (top && !top->sha1)
+	{
+		top->sha1 = root;
+		top->path = name;
+		top->len = 0;
+	}
+
 	if (!size) {
 		retval = -1;
 	} else {
 		struct tree_desc t;
 		init_tree_desc(&t, tree, size);
-		retval = find_tree_entry(&t, name, sha1, mode);
+		retval = find_tree_entry(&t, name, sha1, mode, top);
 	}
 	free(tree);
 	return retval;
@@ -602,7 +642,7 @@ enum follow_symlinks_result get_tree_entry_follow_symlinks(unsigned char *tree_s
 
 		/* Look up the first (or only) path component in the tree. */
 		find_result = find_tree_entry(&t, namebuf.buf,
-					      current_tree_sha1, mode);
+					      current_tree_sha1, mode, NULL);
 		if (find_result) {
 			goto done;
 		}