merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 103 insertions, 41 deletions

diff --git a/third_party/git/t/lib-submodule-update.sh b/third_party/git/t/lib-submodule-update.sh
index 1dd17fc03e12..87a759149faf 100755..100644
--- a/third_party/git/t/lib-submodule-update.sh
+++ b/third_party/git/t/lib-submodule-update.sh
@@ -183,7 +183,7 @@ test_git_directory_is_unchanged () {
 	)
 }
 
-test_git_directory_exists() {
+test_git_directory_exists () {
 	test -e ".git/modules/$1" &&
 	if test -f sub1/.git
 	then
@@ -196,7 +196,6 @@ test_git_directory_exists() {
 # the submodule repo if it doesn't exist and configures the most problematic
 # settings for diff.ignoreSubmodules.
 prolog () {
-	test_oid_init &&
 	(test -d submodule_update_repo || create_lib_submodule_repo) &&
 	test_config_global diff.ignoreSubmodules all &&
 	test_config diff.ignoreSubmodules all
@@ -297,19 +296,23 @@ test_submodule_content () {
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # The default is that submodule contents aren't changed until "git submodule
 # update" is run. And even then that command doesn't delete the work tree of
 # a removed submodule.
 #
+# The first argument of the callback function will be the name of the submodule.
+#
 # Removing a submodule containing a .git directory must fail even when forced
-# to protect the history!
+# to protect the history! If we are testing this case, the second argument of
+# the callback function will be 'test_must_fail', else it will be the empty
+# string.
 #
 
-# Internal function; use test_submodule_switch() or
-# test_submodule_forced_switch() instead.
-test_submodule_switch_common() {
+# Internal function; use test_submodule_switch_func(), test_submodule_switch(),
+# or test_submodule_forced_switch() instead.
+test_submodule_switch_common () {
 	command="$1"
 	######################### Appearing submodule #########################
 	# Switching to a commit letting a submodule appear creates empty dir ...
@@ -443,7 +446,7 @@ test_submodule_switch_common() {
 		(
 			cd submodule_update &&
 			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
-			test_must_fail $command replace_sub1_with_directory &&
+			$command replace_sub1_with_directory test_must_fail &&
 			test_superproject_content origin/add_sub1 &&
 			test_submodule_content sub1 origin/add_sub1
 		)
@@ -456,7 +459,7 @@ test_submodule_switch_common() {
 			cd submodule_update &&
 			git branch -t replace_sub1_with_directory origin/replace_sub1_with_directory &&
 			replace_gitfile_with_git_dir sub1 &&
-			test_must_fail $command replace_sub1_with_directory &&
+			$command replace_sub1_with_directory test_must_fail &&
 			test_superproject_content origin/add_sub1 &&
 			test_git_directory_is_unchanged sub1 &&
 			test_submodule_content sub1 origin/add_sub1
@@ -470,7 +473,7 @@ test_submodule_switch_common() {
 		(
 			cd submodule_update &&
 			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
-			test_must_fail $command replace_sub1_with_file &&
+			$command replace_sub1_with_file test_must_fail &&
 			test_superproject_content origin/add_sub1 &&
 			test_submodule_content sub1 origin/add_sub1
 		)
@@ -484,7 +487,7 @@ test_submodule_switch_common() {
 			cd submodule_update &&
 			git branch -t replace_sub1_with_file origin/replace_sub1_with_file &&
 			replace_gitfile_with_git_dir sub1 &&
-			test_must_fail $command replace_sub1_with_file &&
+			$command replace_sub1_with_file test_must_fail &&
 			test_superproject_content origin/add_sub1 &&
 			test_git_directory_is_unchanged sub1 &&
 			test_submodule_content sub1 origin/add_sub1
@@ -559,15 +562,28 @@ test_submodule_switch_common() {
 # conditions, set the appropriate KNOWN_FAILURE_* variable used in the tests
 # below to 1.
 #
-# Use as follows:
+# The first argument of the callback function will be the name of the submodule.
+#
+# Removing a submodule containing a .git directory must fail even when forced
+# to protect the history! If we are testing this case, the second argument of
+# the callback function will be 'test_must_fail', else it will be the empty
+# string.
+#
+# The following example uses `git some-command` as an example command to be
+# tested. It updates the worktree and index to match a target, but not any
+# submodule directories.
 #
 # my_func () {
-#   target=$1
-#   # Do something here that updates the worktree and index to match target,
-#   # but not any submodule directories.
+#   ...prepare for `git some-command` to be run...
+#   $2 git some-command "$1" &&
+#   if test -n "$2"
+#   then
+#     return
+#   fi &&
+#   ...check the state after git some-command is run...
 # }
-# test_submodule_switch "my_func"
-test_submodule_switch () {
+# test_submodule_switch_func "my_func"
+test_submodule_switch_func () {
 	command="$1"
 	test_submodule_switch_common "$command"
 
@@ -580,17 +596,33 @@ test_submodule_switch () {
 			cd submodule_update &&
 			git branch -t add_sub1 origin/add_sub1 &&
 			>sub1 &&
-			test_must_fail $command add_sub1 &&
+			$command add_sub1 test_must_fail &&
 			test_superproject_content origin/no_submodule &&
 			test_must_be_empty sub1
 		)
 	'
 }
 
+# Ensures that the that the arg either contains "test_must_fail" or is empty.
+may_only_be_test_must_fail () {
+	test -z "$1" || test "$1" = test_must_fail || die
+}
+
+git_test_func () {
+	may_only_be_test_must_fail "$2" &&
+	$2 git $gitcmd "$1"
+}
+
+test_submodule_switch () {
+	gitcmd="$1"
+	test_submodule_switch_func "git_test_func"
+}
+
 # Same as test_submodule_switch(), except that throwing away local changes in
 # the superproject is allowed.
 test_submodule_forced_switch () {
-	command="$1"
+	gitcmd="$1"
+	command="git_test_func"
 	KNOWN_FAILURE_FORCED_SWITCH_TESTS=1
 	test_submodule_switch_common "$command"
 
@@ -621,16 +653,18 @@ test_submodule_forced_switch () {
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # New test cases
 # - Removing a submodule with a git directory absorbs the submodules
 #   git directory first into the superproject.
+# - Switching from no submodule to nested submodules
+# - Switching from nested submodules to no submodule
 
 # Internal function; use test_submodule_switch_recursing_with_args() or
 # test_submodule_forced_switch_recursing_with_args() instead.
-test_submodule_recursing_with_args_common() {
-	command="$1"
+test_submodule_recursing_with_args_common () {
+	command="$1 --recurse-submodules"
 
 	######################### Appearing submodule #########################
 	# Switching to a commit letting a submodule appear checks it out ...
@@ -658,22 +692,6 @@ test_submodule_recursing_with_args_common() {
 			test_submodule_content sub1 origin/add_sub1
 		)
 	'
-	test_expect_success "$command: submodule branch is not changed, detach HEAD instead" '
-		prolog &&
-		reset_work_tree_to_interested add_sub1 &&
-		(
-			cd submodule_update &&
-			git -C sub1 checkout -b keep_branch &&
-			git -C sub1 rev-parse HEAD >expect &&
-			git branch -t modify_sub1 origin/modify_sub1 &&
-			$command modify_sub1 &&
-			test_superproject_content origin/modify_sub1 &&
-			test_submodule_content sub1 origin/modify_sub1 &&
-			git -C sub1 rev-parse keep_branch >actual &&
-			test_cmp expect actual &&
-			test_must_fail git -C sub1 symbolic-ref HEAD
-		)
-	'
 
 	# Replacing a tracked file with a submodule produces a checked out submodule
 	test_expect_success "$command: replace tracked file with submodule checks out submodule" '
@@ -699,6 +717,19 @@ test_submodule_recursing_with_args_common() {
 			test_submodule_content sub1 origin/replace_directory_with_sub1
 		)
 	'
+	# Switching to a commit with nested submodules recursively checks them out
+	test_expect_success "$command: nested submodules are checked out" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t modify_sub1_recursively origin/modify_sub1_recursively &&
+			$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
+		)
+	'
 
 	######################## Disappearing submodule #######################
 	# Removing a submodule removes its work tree ...
@@ -762,6 +793,21 @@ test_submodule_recursing_with_args_common() {
 		)
 	'
 
+	# Switching to a commit without nested submodules removes their worktrees
+	test_expect_success "$command: worktrees of nested submodules are removed" '
+		prolog &&
+		reset_work_tree_to_interested add_nested_sub &&
+		(
+			cd submodule_update &&
+			git branch -t no_submodule origin/no_submodule &&
+			$command no_submodule &&
+			test_superproject_content origin/no_submodule &&
+			! test_path_is_dir sub1 &&
+			test_must_fail git config -f .git/modules/sub1/config core.worktree &&
+			test_must_fail git config -f .git/modules/sub1/modules/sub2/config core.worktree
+		)
+	'
+
 	########################## Modified submodule #########################
 	# Updating a submodule sha1 updates the submodule's work tree
 	test_expect_success "$command: modified submodule updates submodule work tree" '
@@ -789,6 +835,23 @@ test_submodule_recursing_with_args_common() {
 			test_submodule_content sub1 origin/add_sub1
 		)
 	'
+	# Updating a submodule does not touch the currently checked out branch in the submodule
+	test_expect_success "$command: submodule branch is not changed, detach HEAD instead" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git -C sub1 checkout -b keep_branch &&
+			git -C sub1 rev-parse HEAD >expect &&
+			git branch -t modify_sub1 origin/modify_sub1 &&
+			$command modify_sub1 &&
+			test_superproject_content origin/modify_sub1 &&
+			test_submodule_content sub1 origin/modify_sub1 &&
+			git -C sub1 rev-parse keep_branch >actual &&
+			test_cmp expect actual &&
+			test_must_fail git -C sub1 symbolic-ref HEAD
+		)
+	'
 }
 
 # Declares and invokes several tests that, in various situations, checks that
@@ -809,7 +872,7 @@ test_submodule_recursing_with_args_common() {
 # test_submodule_switch_recursing_with_args "$GIT_COMMAND"
 test_submodule_switch_recursing_with_args () {
 	cmd_args="$1"
-	command="git $cmd_args --recurse-submodules"
+	command="git $cmd_args"
 	test_submodule_recursing_with_args_common "$command"
 
 	RESULTDS=success
@@ -908,7 +971,6 @@ test_submodule_switch_recursing_with_args () {
 		)
 	'
 
-	# recursing deeper than one level doesn't work yet.
 	test_expect_success "$command: modified submodule updates submodule recursively" '
 		prolog &&
 		reset_work_tree_to_interested add_nested_sub &&
@@ -927,7 +989,7 @@ test_submodule_switch_recursing_with_args () {
 # away local changes in the superproject is allowed.
 test_submodule_forced_switch_recursing_with_args () {
 	cmd_args="$1"
-	command="git $cmd_args --recurse-submodules"
+	command="git $cmd_args"
 	test_submodule_recursing_with_args_common "$command"
 
 	RESULT=success