[RFCv6 PATCH 00/18] Checkout aware of Submodules!

From

Stefan Beller <sbeller@google.com>

Date

Mar 2, 2017, 00:47 UTC

Message-ID

<20170302004759.27852-1-sbeller@google.com>

In-Reply-To

<20170223225735.10994-1-sbeller@google.com/>

v6:
 * added support for read-tree (see last patch) to see how generic the
   code of the previous patches is. I am pretty pleased with that patch.
 * marked two functions static. Thanks Ramsay!
 * fixed the recursive test; it still fails but it is the code that fails,
   not the test. For this I had to change the setup code slightly.
 * 2 new patches adding tiny refactoring to the submodule test lib.  
 * interdiff (to origin/sb/checkout-recurse-submodules, which is v5) below.

v5:
 * as v4 was the first version queued by Junio, we do have an interdiff below!
 * renamed functions
 * changed the API, now the caller has to take care of the submodule strategy
   themselves. (Note this can be different for different situations, e.g.
   when a submodule is deleted, we can do that for any strategy except none and
   !command. But for moving to a new state of the submodule we currently
   only implement "checkout" [unspecified defaults to checkout]. warning about
   the others, doing nothing there.)

v4:
 * addressed all comments of Brian, Junio and Brandon.
 Thanks!
 * one major point of change is the introduction of another patch
   "lib-submodule-update.sh: do not use ./. as submodule remote",
   as that took some time to track down the existing bug.
 
v3:
 * moved tests from t2013 to the generic submodule library.
 * factored out the refactoring patches to be up front
 * As I redid the complete implementation, I have the impression this time
   it is cleaner than previous versions.
 
 I think we still have to fix the corner cases of directory/file/submodule 
 conflicts before merging, but this serves as a status update on my current
 way of thinking how to implement the worktree commands being aware of
 submodules.
 
Thanks,
Stefan

v2:
* based on top of the series sent out an hour ago
  "[PATCHv4 0/5] submodule embedgitdirs"
* Try to embed a submodule if we need to remove it.
* Strictly do not change behavior if not giving the new flag.
* I think I missed some review comments from v1, but I'd like to get
  the current state out over the weekend, as a lot has changed so far.
  On Monday I'll go through the previous discussion with a comb to see
  if I missed something.
  
v1:
When working with submodules, nearly anytime after checking out
a different state of the projects, that has submodules changed
you'd run "git submodule update" with a current version of Git.

There are two problems with this approach:

* The "submodule update" command is dangerous as it
  doesn't check for work that may be lost in the submodule
  (e.g. a dangling commit).
* you may forget to run the command as checkout is supposed
  to do all the work for you.

Any review, specifically on the design level welcome!

Stefan Beller (14):
  lib-submodule-update.sh: reorder create_lib_submodule_repo
  lib-submodule-update.sh: define tests for recursing into submodules
  make is_submodule_populated gently
  connect_work_tree_and_git_dir: safely create leading directories
  update submodules: add submodule config parsing
  update submodules: add a config option to determine if submodules are
    updated
  update submodules: introduce is_interesting_submodule
  update submodules: move up prepare_submodule_repo_env
  update submodules: add submodule_go_from_to
  unpack-trees: pass old oid to verify_clean_submodule
  unpack-trees: check if we can perform the operation for submodules
  read-cache: remove_marked_cache_entries to wipe selected submodules.
  entry.c: update submodules when interesting
  builtin/checkout: add --recurse-submodules switch

diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index fa1d557e5b..ed9d63ef4a 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt
@@ -115,6 +115,12 @@ OPTIONS
 	directories the index file and index output file are
 	located in.
 
+--[no-]recurse-submodules::
+	Using --recurse-submodules will update the content of all initialized
+	submodules according to the commit recorded in the superproject by
+	calling read-tree recursively, also setting the submodules HEAD to be
+	detached at that commit.
+
 --no-sparse-checkout::
 	Disable sparse checkout support even if `core.sparseCheckout`
 	is true.
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 207ce09771..e9c5fcfaf8 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -29,8 +29,8 @@ static const char * const checkout_usage[] = {
 	NULL,
 };
 
-int option_parse_recurse_submodules(const struct option *opt,
-				    const char *arg, int unset)
+static int option_parse_recurse_submodules(const struct option *opt,
+					   const char *arg, int unset)
 {
 	if (unset) {
 		recurse_submodules = RECURSE_SUBMODULES_OFF;
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 8ba64bc785..2dc5cc06da 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -15,10 +15,13 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "resolve-undo.h"
+#include "submodule.h"
+#include "submodule-config.h"
 
 static int nr_trees;
 static int read_empty;
 static struct tree *trees[MAX_UNPACK_TREES];
+int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
 
 static int list_tree(unsigned char *sha1)
 {
@@ -96,6 +99,23 @@ static int debug_merge(const struct cache_entry * const *stages,
 	return 0;
 }
 
+static int option_parse_recurse_submodules(const struct option *opt,
+					   const char *arg, int unset)
+{
+	if (unset) {
+		recurse_submodules = RECURSE_SUBMODULES_OFF;
+		return 0;
+	}
+	if (arg)
+		recurse_submodules =
+			parse_update_recurse_submodules_arg(opt->long_name,
+							    arg);
+	else
+		recurse_submodules = RECURSE_SUBMODULES_ON;
+
+	return 0;
+}
+
 static struct lock_file lock_file;
 
 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
@@ -137,6 +157,9 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 			 N_("skip applying sparse checkout filter")),
 		OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 			 N_("debug unpack-trees")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_END()
 	};
 
@@ -152,6 +175,12 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 
 	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
+	if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
+		gitmodules_config();
+		git_config(submodule_config, NULL);
+		set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
+	}
+
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
diff --git a/submodule.c b/submodule.c
index a2cf8c9376..bc5fecf8c5 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1257,7 +1257,7 @@ static int submodule_has_dirty_index(const struct submodule *sub)
 	return finish_command(&cp);
 }
 
-void submodule_reset_index(const char *path)
+static void submodule_reset_index(const char *path)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 	prepare_submodule_repo_env_no_git_dir(&cp.env_array);
diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
index 54cd8a6366..429cd1041d 100755
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -4,7 +4,7 @@
 # - New submodule (no_submodule => add_sub1)
 # - Removed submodule (add_sub1 => remove_sub1)
 # - Updated submodule (add_sub1 => modify_sub1)
-# - Updated submodule recursively (modify_sub1 => modify_sub1_recursively)
+# - Updated submodule recursively (add_nested_sub => modify_sub1_recursively)
 # - Submodule updated to invalid commit (add_sub1 => invalid_sub1)
 # - Submodule updated from invalid commit (invalid_sub1 => valid_sub1)
 # - Submodule replaced by tracked files in directory (add_sub1 =>
@@ -20,8 +20,8 @@
 #                    /    ^
 #                   /     remove_sub1
 #                  /
-#       add_sub1  /-------O---------O
-#             |  /        ^         modify_sub1_recursive
+#       add_sub1  /-------O---------O--------O  modify_sub1_recursively
+#             |  /        ^         add_nested_sub
 #             | /         modify_sub1
 #             v/
 #      O------O-----------O---------O
@@ -96,12 +96,24 @@ create_lib_submodule_repo () {
 		git add sub1 &&
 		git commit -m "Modify sub1" &&
 
-		git checkout -b modify_sub1_recursively modify_sub1 &&
+		git checkout -b add_nested_sub modify_sub1 &&
 		git -C sub1 checkout -b "add_nested_sub" &&
 		git -C sub1 submodule add --branch no_submodule ../submodule_update_sub2 sub2 &&
 		git -C sub1 commit -a -m "add a nested submodule" &&
 		git add sub1 &&
 		git commit -a -m "update submodule, that updates a nested submodule" &&
+		git checkout -b modify_sub1_recursively &&
+		git -C sub1 checkout -b modify_sub1_recursively &&
+		git -C sub1/sub2 checkout -b modify_sub1_recursively &&
+		echo change >sub1/sub2/file3 &&
+		git -C sub1/sub2 add file3 &&
+		git -C sub1/sub2 commit -m "make a change in nested sub" &&
+		git -C sub1 add sub2 &&
+		git -C sub1 commit -m "update nested sub" &&
+		git add sub1 &&
+		git commit -m "update sub1, that updates nested sub" &&
+		git -C sub1 push origin modify_sub1_recursively &&
+		git -C sub1/sub2 push origin modify_sub1_recursively &&
 		git -C sub1 submodule deinit -f --all &&
 
 		git checkout -b replace_sub1_with_directory add_sub1 &&
@@ -200,9 +212,9 @@ reset_work_tree_to () {
 		git checkout -f "$1" &&
 		git status -u -s >actual &&
 		test_must_be_empty actual &&
-		sha1=$(git rev-parse --revs-only HEAD:sub1) &&
-		if test -n "$sha1" &&
-		   test $(cd "../submodule_update_sub1" && git rev-parse --verify "$sha1^{commit}")
+		hash=$(git rev-parse --revs-only HEAD:sub1) &&
+		if test -n "$hash" &&
+		   test $(cd "../submodule_update_sub1" && git rev-parse --verify "$hash^{commit}")
 		then
 			git submodule update --init --recursive "sub1"
 		fi
@@ -211,14 +223,23 @@ reset_work_tree_to () {
 
 reset_work_tree_to_interested () {
 	reset_work_tree_to $1 &&
-	# indicate we are interested in the submodule:
-	git -C submodule_update config submodule.sub1.url "bogus" &&
-	# also have it available:
+	# make the submodule git dirs available
 	if ! test -d submodule_update/.git/modules/sub1
 	then
 		mkdir -p submodule_update/.git/modules &&
 		cp -r submodule_update_repo/.git/modules/sub1 submodule_update/.git/modules/sub1
-	fi
+		GIT_WORK_TREE=. git -C submodule_update/.git/modules/sub1 config --unset core.worktree
+	fi &&
+	if ! test -d submodule_update/.git/modules/sub1/modules/sub2
+	then
+		mkdir -p submodule_update/.git/modules/sub1/modules &&
+		cp -r submodule_update_repo/.git/modules/sub1/modules/sub2 submodule_update/.git/modules/sub1/modules/sub2
+		GIT_WORK_TREE=. git -C submodule_update/.git/modules/sub1/modules/sub2 config --unset core.worktree
+	fi &&
+	# indicate we are interested in the submodule:
+	git -C submodule_update config submodule.sub1.url "bogus" &&
+	# sub1 might not be checked out, so use the git dir
+	git -C submodule_update/.git/modules/sub1 config submodule.sub2.url "bogus"
 }
 
 # Test that the superproject contains the content according to commit "$1"
@@ -234,6 +255,11 @@ test_superproject_content () {
 # Test that the given submodule at path "$1" contains the content according
 # to the submodule commit recorded in the superproject's commit "$2"
 test_submodule_content () {
+	if test "$1" == "-C"
+	then
+		cd "$2"
+		shift; shift;
+	fi
 	if test $# != 2
 	then
 		echo "test_submodule_content needs two arguments"
@@ -761,6 +787,11 @@ test_submodule_switch_recursing () {
 	then
 		RESULT=failure
 	fi
+
+	if test "$KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED" = 1
+	then
+		RESULT1=failure
+	fi
 	######################### Appearing submodule #########################
 	# Switching to a commit letting a submodule appear checks it out ...
 	test_expect_success "$command: added submodule is checked out" '
@@ -801,7 +832,7 @@ test_submodule_switch_recursing () {
 		)
 	'
 	# ... but an ignored file is fine.
-	test_expect_success "$command: added submodule removes an untracked ignored file" '
+	test_expect_$RESULT1 "$command: added submodule removes an untracked ignored file" '
 		test_when_finished "rm submodule_update/.git/info/exclude" &&
 		prolog &&
 		reset_work_tree_to_interested no_submodule &&
@@ -966,21 +997,17 @@ test_submodule_switch_recursing () {
 		)
 	'
 
-	# This test fails, due to missing setup, we do not clone sub2 into
-	# submodule_update, because it doesn't exist in the 'add_sub1' version
-	#
-	test_expect_success "$command: modified submodule updates submodule recursively" '
+	# recursing deeper than one level doesn't work yet.
+	test_expect_failure "$command: modified submodule updates submodule recursively" '
 		prolog &&
-		reset_work_tree_to_interested add_sub1 &&
+		reset_work_tree_to_interested add_nested_sub &&
 		(
 			cd submodule_update &&
 			git branch -t modify_sub1_recursively origin/modify_sub1_recursively &&
-			test_must_fail $command modify_sub1_recursively &&
-			test_superproject_content origin/add_sub1 &&
-			test_submodule_content sub1 origin/add_sub1
-			# test_superproject_content origin/modify_sub1_recursively &&
-			# test_submodule_content sub1 origin/modify_sub1_recursively &&
-			# test_submodule_content sub1/sub2 no_submodule
+			$command modify_sub1_recursively &&
+			test_superproject_content origin/modify_sub1_recursively &&
+			test_submodule_content sub1 origin/modify_sub1_recursively &&
+			test_submodule_content -C sub1 sub2 origin/modify_sub1_recursively
 		)
 	'
 }
diff --git a/t/t1013-read-tree-submodule.sh b/t/t1013-read-tree-submodule.sh
index 20526aed34..7019d0a04f 100755
--- a/t/t1013-read-tree-submodule.sh
+++ b/t/t1013-read-tree-submodule.sh
@@ -5,6 +5,13 @@ test_description='read-tree can handle submodules'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
+KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS=1
+KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED=1
+
+test_submodule_switch_recursing "git read-tree --recurse-submodules -u -m"
+
+test_submodule_forced_switch_recursing "git read-tree --recurse-submodules -u --reset"
+
 test_submodule_switch "git read-tree -u -m"
 
 test_submodule_forced_switch "git read-tree -u --reset"