Merge branch 'sb/unpack-trees-super-prefix'

"git read-tree" and its underlying unpack_trees() machinery learned
to report problematic paths prefixed with the --super-prefix option.

* sb/unpack-trees-super-prefix:
  unpack-trees: support super-prefix option
  t1001: modernize style
  t1000: modernize style
  read-tree: use OPT_BOOL instead of OPT_SET_INT

5 files changed, 702 insertions, 676 deletions

diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index fa6edb35b2..8ba64bc785 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -109,34 +109,34 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 		{ OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
 		  N_("write resulting index to <file>"),
 		  PARSE_OPT_NONEG, index_output_cb },
-		OPT_SET_INT(0, "empty", &read_empty,
-			    N_("only empty the index"), 1),
+		OPT_BOOL(0, "empty", &read_empty,
+			    N_("only empty the index")),
 		OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
 		OPT_GROUP(N_("Merging")),
-		OPT_SET_INT('m', NULL, &opts.merge,
-			    N_("perform a merge in addition to a read"), 1),
-		OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
-			    N_("3-way merge if no file level merging required"), 1),
-		OPT_SET_INT(0, "aggressive", &opts.aggressive,
-			    N_("3-way merge in presence of adds and removes"), 1),
-		OPT_SET_INT(0, "reset", &opts.reset,
-			    N_("same as -m, but discard unmerged entries"), 1),
+		OPT_BOOL('m', NULL, &opts.merge,
+			 N_("perform a merge in addition to a read")),
+		OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
+			 N_("3-way merge if no file level merging required")),
+		OPT_BOOL(0, "aggressive", &opts.aggressive,
+			 N_("3-way merge in presence of adds and removes")),
+		OPT_BOOL(0, "reset", &opts.reset,
+			 N_("same as -m, but discard unmerged entries")),
 		{ OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 		  N_("read the tree into the index under <subdirectory>/"),
 		  PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
-		OPT_SET_INT('u', NULL, &opts.update,
-			    N_("update working tree with merge result"), 1),
+		OPT_BOOL('u', NULL, &opts.update,
+			 N_("update working tree with merge result")),
 		{ OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
 		  N_("gitignore"),
 		  N_("allow explicitly ignored files to be overwritten"),
 		  PARSE_OPT_NONEG, exclude_per_directory_cb },
-		OPT_SET_INT('i', NULL, &opts.index_only,
-			    N_("don't check the working tree after merging"), 1),
+		OPT_BOOL('i', NULL, &opts.index_only,
+			 N_("don't check the working tree after merging")),
 		OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
-		OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
-			    N_("skip applying sparse checkout filter"), 1),
-		OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
-			    N_("debug unpack-trees"), 1),
+		OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
+			 N_("skip applying sparse checkout filter")),
+		OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
+			 N_("debug unpack-trees")),
 		OPT_END()
 	};
 
diff --git a/git.c b/git.c
index 1cf125cd28..c887272b12 100644
--- a/git.c
+++ b/git.c
@@ -472,7 +472,7 @@ static struct cmd_struct commands[] = {
 	{ "prune-packed", cmd_prune_packed, RUN_SETUP },
 	{ "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 	{ "push", cmd_push, RUN_SETUP },
-	{ "read-tree", cmd_read_tree, RUN_SETUP },
+	{ "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
 	{ "receive-pack", cmd_receive_pack },
 	{ "reflog", cmd_reflog, RUN_SETUP },
 	{ "remote", cmd_remote, RUN_SETUP },
diff --git a/t/t1000-read-tree-m-3way.sh b/t/t1000-read-tree-m-3way.sh
index a0b79b4839..3c4d2d6045 100755
--- a/t/t1000-read-tree-m-3way.sh
+++ b/t/t1000-read-tree-m-3way.sh
@@ -128,29 +128,29 @@ cat >expected <<\EOF
 EOF
 
 check_result () {
-    git ls-files --stage | sed -e 's/ '"$_x40"' / X /' >current &&
-    test_cmp expected current
+	git ls-files --stage | sed -e 's/ '"$_x40"' / X /' >current &&
+	test_cmp expected current
 }
 
 # This is done on an empty work directory, which is the normal
 # merge person behaviour.
-test_expect_success \
-    '3-way merge with git read-tree -m, empty cache' \
-    "rm -fr [NDMALTS][NDMALTSF] Z &&
-     rm .git/index &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
+test_expect_success '3-way merge with git read-tree -m, empty cache' '
+	rm -fr [NDMALTS][NDMALTSF] Z &&
+	rm .git/index &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
 
 # This starts out with the first head, which is the normal
 # patch submitter behaviour.
-test_expect_success \
-    '3-way merge with git read-tree -m, match H' \
-    "rm -fr [NDMALTS][NDMALTSF] Z &&
-     rm .git/index &&
-     read_tree_must_succeed $tree_A &&
-     git checkout-index -f -u -a &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
+test_expect_success '3-way merge with git read-tree -m, match H' '
+	rm -fr [NDMALTS][NDMALTSF] Z &&
+	rm .git/index &&
+	read_tree_must_succeed $tree_A &&
+	git checkout-index -f -u -a &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
 
 : <<\END_OF_CASE_TABLE
 
@@ -208,322 +208,304 @@ DF (file) when tree B require DF to be a directory by having DF/DF
 
 END_OF_CASE_TABLE
 
-test_expect_success '1 - must not have an entry not in A.' "
-     rm -f .git/index XX &&
-     echo XX >XX &&
-     git update-index --add XX &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '2 - must match B in !O && !A && B case.' \
-    "rm -f .git/index NA &&
-     cp .orig-B/NA NA &&
-     git update-index --add NA &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B"
-
-test_expect_success \
-    '2 - matching B alone is OK in !O && !A && B case.' \
-    "rm -f .git/index NA &&
-     cp .orig-B/NA NA &&
-     git update-index --add NA &&
-     echo extra >>NA &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B"
-
-test_expect_success \
-    '3 - must match A in !O && A && !B case.' \
-    "rm -f .git/index AN &&
-     cp .orig-A/AN AN &&
-     git update-index --add AN &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '3 - matching A alone is OK in !O && A && !B case.' \
-    "rm -f .git/index AN &&
-     cp .orig-A/AN AN &&
-     git update-index --add AN &&
-     echo extra >>AN &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B"
-
-test_expect_success \
-    '3 (fail) - must match A in !O && A && !B case.' "
-     rm -f .git/index AN &&
-     cp .orig-A/AN AN &&
-     echo extra >>AN &&
-     git update-index --add AN &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '4 - must match and be up-to-date in !O && A && B && A!=B case.' \
-    "rm -f .git/index AA &&
-     cp .orig-A/AA AA &&
-     git update-index --add AA &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '4 (fail) - must match and be up-to-date in !O && A && B && A!=B case.' "
-     rm -f .git/index AA &&
-     cp .orig-A/AA AA &&
-     git update-index --add AA &&
-     echo extra >>AA &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '4 (fail) - must match and be up-to-date in !O && A && B && A!=B case.' "
-     rm -f .git/index AA &&
-     cp .orig-A/AA AA &&
-     echo extra >>AA &&
-     git update-index --add AA &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '5 - must match in !O && A && B && A==B case.' \
-    "rm -f .git/index LL &&
-     cp .orig-A/LL LL &&
-     git update-index --add LL &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '5 - must match in !O && A && B && A==B case.' \
-    "rm -f .git/index LL &&
-     cp .orig-A/LL LL &&
-     git update-index --add LL &&
-     echo extra >>LL &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '5 (fail) - must match A in !O && A && B && A==B case.' "
-     rm -f .git/index LL &&
-     cp .orig-A/LL LL &&
-     echo extra >>LL &&
-     git update-index --add LL &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '6 - must not exist in O && !A && !B case' "
-     rm -f .git/index DD &&
-     echo DD >DD &&
-     git update-index --add DD &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '7 - must not exist in O && !A && B && O!=B case' "
-     rm -f .git/index DM &&
-     cp .orig-B/DM DM &&
-     git update-index --add DM &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '8 - must not exist in O && !A && B && O==B case' "
-     rm -f .git/index DN &&
-     cp .orig-B/DN DN &&
-     git update-index --add DN &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '9 - must match and be up-to-date in O && A && !B && O!=A case' \
-    "rm -f .git/index MD &&
-     cp .orig-A/MD MD &&
-     git update-index --add MD &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '9 (fail) - must match and be up-to-date in O && A && !B && O!=A case' "
-     rm -f .git/index MD &&
-     cp .orig-A/MD MD &&
-     git update-index --add MD &&
-     echo extra >>MD &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '9 (fail) - must match and be up-to-date in O && A && !B && O!=A case' "
-     rm -f .git/index MD &&
-     cp .orig-A/MD MD &&
-     echo extra >>MD &&
-     git update-index --add MD &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '10 - must match and be up-to-date in O && A && !B && O==A case' \
-    "rm -f .git/index ND &&
-     cp .orig-A/ND ND &&
-     git update-index --add ND &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '10 (fail) - must match and be up-to-date in O && A && !B && O==A case' "
-     rm -f .git/index ND &&
-     cp .orig-A/ND ND &&
-     git update-index --add ND &&
-     echo extra >>ND &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '10 (fail) - must match and be up-to-date in O && A && !B && O==A case' "
-     rm -f .git/index ND &&
-     cp .orig-A/ND ND &&
-     echo extra >>ND &&
-     git update-index --add ND &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '11 - must match and be up-to-date in O && A && B && O!=A && O!=B && A!=B case' \
-    "rm -f .git/index MM &&
-     cp .orig-A/MM MM &&
-     git update-index --add MM &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '11 (fail) - must match and be up-to-date in O && A && B && O!=A && O!=B && A!=B case' "
-     rm -f .git/index MM &&
-     cp .orig-A/MM MM &&
-     git update-index --add MM &&
-     echo extra >>MM &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '11 (fail) - must match and be up-to-date in O && A && B && O!=A && O!=B && A!=B case' "
-     rm -f .git/index MM &&
-     cp .orig-A/MM MM &&
-     echo extra >>MM &&
-     git update-index --add MM &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '12 - must match A in O && A && B && O!=A && A==B case' \
-    "rm -f .git/index SS &&
-     cp .orig-A/SS SS &&
-     git update-index --add SS &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '12 - must match A in O && A && B && O!=A && A==B case' \
-    "rm -f .git/index SS &&
-     cp .orig-A/SS SS &&
-     git update-index --add SS &&
-     echo extra >>SS &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '12 (fail) - must match A in O && A && B && O!=A && A==B case' "
-     rm -f .git/index SS &&
-     cp .orig-A/SS SS &&
-     echo extra >>SS &&
-     git update-index --add SS &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '13 - must match A in O && A && B && O!=A && O==B case' \
-    "rm -f .git/index MN &&
-     cp .orig-A/MN MN &&
-     git update-index --add MN &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '13 - must match A in O && A && B && O!=A && O==B case' \
-    "rm -f .git/index MN &&
-     cp .orig-A/MN MN &&
-     git update-index --add MN &&
-     echo extra >>MN &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '14 - must match and be up-to-date in O && A && B && O==A && O!=B case' \
-    "rm -f .git/index NM &&
-     cp .orig-A/NM NM &&
-     git update-index --add NM &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '14 - may match B in O && A && B && O==A && O!=B case' \
-    "rm -f .git/index NM &&
-     cp .orig-B/NM NM &&
-     git update-index --add NM &&
-     echo extra >>NM &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '14 (fail) - must match and be up-to-date in O && A && B && O==A && O!=B case' "
-     rm -f .git/index NM &&
-     cp .orig-A/NM NM &&
-     git update-index --add NM &&
-     echo extra >>NM &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '14 (fail) - must match and be up-to-date in O && A && B && O==A && O!=B case' "
-     rm -f .git/index NM &&
-     cp .orig-A/NM NM &&
-     echo extra >>NM &&
-     git update-index --add NM &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-test_expect_success \
-    '15 - must match A in O && A && B && O==A && O==B case' \
-    "rm -f .git/index NN &&
-     cp .orig-A/NN NN &&
-     git update-index --add NN &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '15 - must match A in O && A && B && O==A && O==B case' \
-    "rm -f .git/index NN &&
-     cp .orig-A/NN NN &&
-     git update-index --add NN &&
-     echo extra >>NN &&
-     read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
-     check_result"
-
-test_expect_success \
-    '15 (fail) - must match A in O && A && B && O==A && O==B case' "
-     rm -f .git/index NN &&
-     cp .orig-A/NN NN &&
-     echo extra >>NN &&
-     git update-index --add NN &&
-     read_tree_must_fail -m $tree_O $tree_A $tree_B
-"
-
-# #16
-test_expect_success \
-    '16 - A matches in one and B matches in another.' \
-    'rm -f .git/index F16 &&
-    echo F16 >F16 &&
-    git update-index --add F16 &&
-    tree0=$(git write-tree) &&
-    echo E16 >F16 &&
-    git update-index F16 &&
-    tree1=$(git write-tree) &&
-    read_tree_must_succeed -m $tree0 $tree1 $tree1 $tree0 &&
-    git ls-files --stage'
+test_expect_success '1 - must not have an entry not in A.' '
+	rm -f .git/index XX &&
+	echo XX >XX &&
+	git update-index --add XX &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '2 - must match B in !O && !A && B case.' '
+	rm -f .git/index NA &&
+	cp .orig-B/NA NA &&
+	git update-index --add NA &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '2 - matching B alone is OK in !O && !A && B case.' '
+	rm -f .git/index NA &&
+	cp .orig-B/NA NA &&
+	git update-index --add NA &&
+	echo extra >>NA &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '3 - must match A in !O && A && !B case.' '
+	rm -f .git/index AN &&
+	cp .orig-A/AN AN &&
+	git update-index --add AN &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '3 - matching A alone is OK in !O && A && !B case.' '
+	rm -f .git/index AN &&
+	cp .orig-A/AN AN &&
+	git update-index --add AN &&
+	echo extra >>AN &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '3 (fail) - must match A in !O && A && !B case.' '
+	rm -f .git/index AN &&
+	cp .orig-A/AN AN &&
+	echo extra >>AN &&
+	git update-index --add AN &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '4 - must match and be up-to-date in !O && A && B && A!=B case.' '
+	rm -f .git/index AA &&
+	cp .orig-A/AA AA &&
+	git update-index --add AA &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '4 (fail) - must match and be up-to-date in !O && A && B && A!=B case.' '
+	rm -f .git/index AA &&
+	cp .orig-A/AA AA &&
+	git update-index --add AA &&
+	echo extra >>AA &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '4 (fail) - must match and be up-to-date in !O && A && B && A!=B case.' '
+	rm -f .git/index AA &&
+	cp .orig-A/AA AA &&
+	echo extra >>AA &&
+	git update-index --add AA &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '5 - must match in !O && A && B && A==B case.' '
+	rm -f .git/index LL &&
+	cp .orig-A/LL LL &&
+	git update-index --add LL &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '5 - must match in !O && A && B && A==B case.' '
+	rm -f .git/index LL &&
+	cp .orig-A/LL LL &&
+	git update-index --add LL &&
+	echo extra >>LL &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '5 (fail) - must match A in !O && A && B && A==B case.' '
+	rm -f .git/index LL &&
+	cp .orig-A/LL LL &&
+	echo extra >>LL &&
+	git update-index --add LL &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '6 - must not exist in O && !A && !B case' '
+	rm -f .git/index DD &&
+	echo DD >DD &&
+	git update-index --add DD &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '7 - must not exist in O && !A && B && O!=B case' '
+	rm -f .git/index DM &&
+	cp .orig-B/DM DM &&
+	git update-index --add DM &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '8 - must not exist in O && !A && B && O==B case' '
+	rm -f .git/index DN &&
+	cp .orig-B/DN DN &&
+	git update-index --add DN &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '9 - must match and be up-to-date in O && A && !B && O!=A case' '
+	rm -f .git/index MD &&
+	cp .orig-A/MD MD &&
+	git update-index --add MD &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '9 (fail) - must match and be up-to-date in O && A && !B && O!=A case' '
+	rm -f .git/index MD &&
+	cp .orig-A/MD MD &&
+	git update-index --add MD &&
+	echo extra >>MD &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '9 (fail) - must match and be up-to-date in O && A && !B && O!=A case' '
+	rm -f .git/index MD &&
+	cp .orig-A/MD MD &&
+	echo extra >>MD &&
+	git update-index --add MD &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '10 - must match and be up-to-date in O && A && !B && O==A case' '
+	rm -f .git/index ND &&
+	cp .orig-A/ND ND &&
+	git update-index --add ND &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '10 (fail) - must match and be up-to-date in O && A && !B && O==A case' '
+	rm -f .git/index ND &&
+	cp .orig-A/ND ND &&
+	git update-index --add ND &&
+	echo extra >>ND &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '10 (fail) - must match and be up-to-date in O && A && !B && O==A case' '
+	rm -f .git/index ND &&
+	cp .orig-A/ND ND &&
+	echo extra >>ND &&
+	git update-index --add ND &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '11 - must match and be up-to-date in O && A && B && O!=A && O!=B && A!=B case' '
+	rm -f .git/index MM &&
+	cp .orig-A/MM MM &&
+	git update-index --add MM &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '11 (fail) - must match and be up-to-date in O && A && B && O!=A && O!=B && A!=B case' '
+	rm -f .git/index MM &&
+	cp .orig-A/MM MM &&
+	git update-index --add MM &&
+	echo extra >>MM &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '11 (fail) - must match and be up-to-date in O && A && B && O!=A && O!=B && A!=B case' '
+	rm -f .git/index MM &&
+	cp .orig-A/MM MM &&
+	echo extra >>MM &&
+	git update-index --add MM &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '12 - must match A in O && A && B && O!=A && A==B case' '
+	rm -f .git/index SS &&
+	cp .orig-A/SS SS &&
+	git update-index --add SS &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '12 - must match A in O && A && B && O!=A && A==B case' '
+	rm -f .git/index SS &&
+	cp .orig-A/SS SS &&
+	git update-index --add SS &&
+	echo extra >>SS &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '12 (fail) - must match A in O && A && B && O!=A && A==B case' '
+	rm -f .git/index SS &&
+	cp .orig-A/SS SS &&
+	echo extra >>SS &&
+	git update-index --add SS &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '13 - must match A in O && A && B && O!=A && O==B case' '
+	rm -f .git/index MN &&
+	cp .orig-A/MN MN &&
+	git update-index --add MN &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '13 - must match A in O && A && B && O!=A && O==B case' '
+	rm -f .git/index MN &&
+	cp .orig-A/MN MN &&
+	git update-index --add MN &&
+	echo extra >>MN &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '14 - must match and be up-to-date in O && A && B && O==A && O!=B case' '
+	rm -f .git/index NM &&
+	cp .orig-A/NM NM &&
+	git update-index --add NM &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '14 - may match B in O && A && B && O==A && O!=B case' '
+	rm -f .git/index NM &&
+	cp .orig-B/NM NM &&
+	git update-index --add NM &&
+	echo extra >>NM &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '14 (fail) - must match and be up-to-date in O && A && B && O==A && O!=B case' '
+	rm -f .git/index NM &&
+	cp .orig-A/NM NM &&
+	git update-index --add NM &&
+	echo extra >>NM &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '14 (fail) - must match and be up-to-date in O && A && B && O==A && O!=B case' '
+	rm -f .git/index NM &&
+	cp .orig-A/NM NM &&
+	echo extra >>NM &&
+	git update-index --add NM &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '15 - must match A in O && A && B && O==A && O==B case' '
+	rm -f .git/index NN &&
+	cp .orig-A/NN NN &&
+	git update-index --add NN &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '15 - must match A in O && A && B && O==A && O==B case' '
+	rm -f .git/index NN &&
+	cp .orig-A/NN NN &&
+	git update-index --add NN &&
+	echo extra >>NN &&
+	read_tree_must_succeed -m $tree_O $tree_A $tree_B &&
+	check_result
+'
+
+test_expect_success '15 (fail) - must match A in O && A && B && O==A && O==B case' '
+	rm -f .git/index NN &&
+	cp .orig-A/NN NN &&
+	echo extra >>NN &&
+	git update-index --add NN &&
+	read_tree_must_fail -m $tree_O $tree_A $tree_B
+'
+
+test_expect_success '16 - A matches in one and B matches in another.' '
+	rm -f .git/index F16 &&
+	echo F16 >F16 &&
+	git update-index --add F16 &&
+	tree0=$(git write-tree) &&
+	echo E16 >F16 &&
+	git update-index F16 &&
+	tree1=$(git write-tree) &&
+	read_tree_must_succeed -m $tree0 $tree1 $tree1 $tree0 &&
+	git ls-files --stage
+'
 
 test_done
diff --git a/t/t1001-read-tree-m-2way.sh b/t/t1001-read-tree-m-2way.sh
index db1b6f5cf4..5ededd8e40 100755
--- a/t/t1001-read-tree-m-2way.sh
+++ b/t/t1001-read-tree-m-2way.sh
@@ -14,10 +14,10 @@ all the combinations described in the two-tree merge "carry forward"
 rules, found in <Documentation/git read-tree.txt>.
 
 In the test, these paths are used:
-        bozbar  - in H, stays in M, modified from bozbar to gnusto
-        frotz   - not in H added in M
-        nitfol  - in H, stays in M unmodified
-        rezrov  - in H, deleted in M
+	bozbar  - in H, stays in M, modified from bozbar to gnusto
+	frotz   - not in H added in M
+	nitfol  - in H, stays in M unmodified
+	rezrov  - in H, deleted in M
 	yomin   - not in H or M
 '
 . ./test-lib.sh
@@ -60,336 +60,343 @@ EOF
 
 sed -e 's/bozbar/gnusto (earlier bozbar)/' bozbar-old >bozbar-new
 
-test_expect_success \
-    setup \
-    'echo frotz >frotz &&
-     echo nitfol >nitfol &&
-     cat bozbar-old >bozbar &&
-     echo rezrov >rezrov &&
-     echo yomin >yomin &&
-     git update-index --add nitfol bozbar rezrov &&
-     treeH=$(git write-tree) &&
-     echo treeH $treeH &&
-     git ls-tree $treeH &&
-
-     cat bozbar-new >bozbar &&
-     git update-index --add frotz bozbar --force-remove rezrov &&
-     git ls-files --stage >M.out &&
-     treeM=$(git write-tree) &&
-     echo treeM $treeM &&
-     git ls-tree $treeM &&
-     git diff-tree $treeH $treeM'
-
-test_expect_success \
-    '1, 2, 3 - no carry forward' \
-    'rm -f .git/index &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >1-3.out &&
-     test_cmp M.out 1-3.out &&
-     check_cache_at bozbar dirty &&
-     check_cache_at frotz dirty &&
-     check_cache_at nitfol dirty'
+test_expect_success 'setup' '
+	echo frotz >frotz &&
+	echo nitfol >nitfol &&
+	cat bozbar-old >bozbar &&
+	echo rezrov >rezrov &&
+	echo yomin >yomin &&
+	git update-index --add nitfol bozbar rezrov &&
+	treeH=$(git write-tree) &&
+	echo treeH $treeH &&
+	git ls-tree $treeH &&
+
+	cat bozbar-new >bozbar &&
+	git update-index --add frotz bozbar --force-remove rezrov &&
+	git ls-files --stage >M.out &&
+	treeM=$(git write-tree) &&
+	echo treeM $treeM &&
+	git ls-tree $treeM &&
+	git diff-tree $treeH $treeM
+'
 
+test_expect_success '1, 2, 3 - no carry forward' '
+	rm -f .git/index &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >1-3.out &&
+	test_cmp M.out 1-3.out &&
+	check_cache_at bozbar dirty &&
+	check_cache_at frotz dirty &&
+	check_cache_at nitfol dirty
+'
 echo '+100644 X 0	yomin' >expected
 
-test_expect_success \
-    '4 - carry forward local addition.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     git update-index --add yomin &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >4.out &&
-     test_must_fail git diff --no-index M.out 4.out >4diff.out &&
-     compare_change 4diff.out expected &&
-     check_cache_at yomin clean'
-
-test_expect_success \
-    '5 - carry forward local addition.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo yomin >yomin &&
-     git update-index --add yomin &&
-     echo yomin yomin >yomin &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >5.out &&
-     test_must_fail git diff --no-index M.out 5.out >5diff.out &&
-     compare_change 5diff.out expected &&
-     check_cache_at yomin dirty'
-
-test_expect_success \
-    '6 - local addition already has the same.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     git update-index --add frotz &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >6.out &&
-     test_cmp M.out 6.out &&
-     check_cache_at frotz clean'
-
-test_expect_success \
-    '7 - local addition already has the same.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo frotz >frotz &&
-     git update-index --add frotz &&
-     echo frotz frotz >frotz &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >7.out &&
-     test_cmp M.out 7.out &&
-     check_cache_at frotz dirty'
-
-test_expect_success \
-    '8 - conflicting addition.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo frotz frotz >frotz &&
-     git update-index --add frotz &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
-
-test_expect_success \
-    '9 - conflicting addition.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo frotz frotz >frotz &&
-     git update-index --add frotz &&
-     echo frotz >frotz &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
-
-test_expect_success \
-    '10 - path removed.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo rezrov >rezrov &&
-     git update-index --add rezrov &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >10.out &&
-     test_cmp M.out 10.out'
-
-test_expect_success \
-    '11 - dirty path removed.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo rezrov >rezrov &&
-     git update-index --add rezrov &&
-     echo rezrov rezrov >rezrov &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
-
-test_expect_success \
-    '12 - unmatching local changes being removed.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo rezrov rezrov >rezrov &&
-     git update-index --add rezrov &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
-
-test_expect_success \
-    '13 - unmatching local changes being removed.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo rezrov rezrov >rezrov &&
-     git update-index --add rezrov &&
-     echo rezrov >rezrov &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
+test_expect_success '4 - carry forward local addition.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	git update-index --add yomin &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >4.out &&
+	test_must_fail git diff --no-index M.out 4.out >4diff.out &&
+	compare_change 4diff.out expected &&
+	check_cache_at yomin clean
+'
+
+test_expect_success '5 - carry forward local addition.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo yomin >yomin &&
+	git update-index --add yomin &&
+	echo yomin yomin >yomin &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >5.out &&
+	test_must_fail git diff --no-index M.out 5.out >5diff.out &&
+	compare_change 5diff.out expected &&
+	check_cache_at yomin dirty
+'
+
+test_expect_success '6 - local addition already has the same.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	git update-index --add frotz &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >6.out &&
+	test_cmp M.out 6.out &&
+	check_cache_at frotz clean
+'
+
+test_expect_success '7 - local addition already has the same.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo frotz >frotz &&
+	git update-index --add frotz &&
+	echo frotz frotz >frotz &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >7.out &&
+	test_cmp M.out 7.out &&
+	check_cache_at frotz dirty
+'
+
+test_expect_success '8 - conflicting addition.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo frotz frotz >frotz &&
+	git update-index --add frotz &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
+
+test_expect_success '9 - conflicting addition.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo frotz frotz >frotz &&
+	git update-index --add frotz &&
+	echo frotz >frotz &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
+
+test_expect_success '10 - path removed.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo rezrov >rezrov &&
+	git update-index --add rezrov &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >10.out &&
+	test_cmp M.out 10.out
+'
+
+test_expect_success '11 - dirty path removed.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo rezrov >rezrov &&
+	git update-index --add rezrov &&
+	echo rezrov rezrov >rezrov &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
+
+test_expect_success '12 - unmatching local changes being removed.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo rezrov rezrov >rezrov &&
+	git update-index --add rezrov &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
+
+test_expect_success '13 - unmatching local changes being removed.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo rezrov rezrov >rezrov &&
+	git update-index --add rezrov &&
+	echo rezrov >rezrov &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
 
 cat >expected <<EOF
 -100644 X 0	nitfol
 +100644 X 0	nitfol
 EOF
 
-test_expect_success \
-    '14 - unchanged in two heads.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo nitfol nitfol >nitfol &&
-     git update-index --add nitfol &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >14.out &&
-     test_must_fail git diff --no-index M.out 14.out >14diff.out &&
-     compare_change 14diff.out expected &&
-     check_cache_at nitfol clean'
-
-test_expect_success \
-    '15 - unchanged in two heads.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo nitfol nitfol >nitfol &&
-     git update-index --add nitfol &&
-     echo nitfol nitfol nitfol >nitfol &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >15.out &&
-     test_must_fail git diff --no-index M.out 15.out >15diff.out &&
-     compare_change 15diff.out expected &&
-     check_cache_at nitfol dirty'
-
-test_expect_success \
-    '16 - conflicting local change.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo bozbar bozbar >bozbar &&
-     git update-index --add bozbar &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
-
-test_expect_success \
-    '17 - conflicting local change.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     echo bozbar bozbar >bozbar &&
-     git update-index --add bozbar &&
-     echo bozbar bozbar bozbar >bozbar &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
-
-test_expect_success \
-    '18 - local change already having a good result.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     cat bozbar-new >bozbar &&
-     git update-index --add bozbar &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >18.out &&
-     test_cmp M.out 18.out &&
-     check_cache_at bozbar clean'
-
-test_expect_success \
-    '19 - local change already having a good result, further modified.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     cat bozbar-new >bozbar &&
-     git update-index --add bozbar &&
-     echo gnusto gnusto >bozbar &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >19.out &&
-     test_cmp M.out 19.out &&
-     check_cache_at bozbar dirty'
-
-test_expect_success \
-    '20 - no local change, use new tree.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     cat bozbar-old >bozbar &&
-     git update-index --add bozbar &&
-     read_tree_twoway $treeH $treeM &&
-     git ls-files --stage >20.out &&
-     test_cmp M.out 20.out &&
-     check_cache_at bozbar dirty'
-
-test_expect_success \
-    '21 - no local change, dirty cache.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     cat bozbar-old >bozbar &&
-     git update-index --add bozbar &&
-     echo gnusto gnusto >bozbar &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
+test_expect_success '14 - unchanged in two heads.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo nitfol nitfol >nitfol &&
+	git update-index --add nitfol &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >14.out &&
+	test_must_fail git diff --no-index M.out 14.out >14diff.out &&
+	compare_change 14diff.out expected &&
+	check_cache_at nitfol clean
+'
+
+test_expect_success '15 - unchanged in two heads.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo nitfol nitfol >nitfol &&
+	git update-index --add nitfol &&
+	echo nitfol nitfol nitfol >nitfol &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >15.out &&
+	test_must_fail git diff --no-index M.out 15.out >15diff.out &&
+	compare_change 15diff.out expected &&
+	check_cache_at nitfol dirty
+'
+
+test_expect_success '16 - conflicting local change.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo bozbar bozbar >bozbar &&
+	git update-index --add bozbar &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
+
+test_expect_success '17 - conflicting local change.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	echo bozbar bozbar >bozbar &&
+	git update-index --add bozbar &&
+	echo bozbar bozbar bozbar >bozbar &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
+
+test_expect_success '18 - local change already having a good result.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	cat bozbar-new >bozbar &&
+	git update-index --add bozbar &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >18.out &&
+	test_cmp M.out 18.out &&
+	check_cache_at bozbar clean
+'
+
+test_expect_success '19 - local change already having a good result, further modified.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	cat bozbar-new >bozbar &&
+	git update-index --add bozbar &&
+	echo gnusto gnusto >bozbar &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >19.out &&
+	test_cmp M.out 19.out &&
+	check_cache_at bozbar dirty
+'
+
+test_expect_success '20 - no local change, use new tree.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	cat bozbar-old >bozbar &&
+	git update-index --add bozbar &&
+	read_tree_twoway $treeH $treeM &&
+	git ls-files --stage >20.out &&
+	test_cmp M.out 20.out &&
+	check_cache_at bozbar dirty
+'
+
+test_expect_success '21 - no local change, dirty cache.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	cat bozbar-old >bozbar &&
+	git update-index --add bozbar &&
+	echo gnusto gnusto >bozbar &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
 
 # This fails with straight two-way fast-forward.
-test_expect_success \
-    '22 - local change cache updated.' \
-    'rm -f .git/index &&
-     read_tree_must_succeed $treeH &&
-     git checkout-index -u -f -q -a &&
-     sed -e "s/such as/SUCH AS/" bozbar-old >bozbar &&
-     git update-index --add bozbar &&
-     if read_tree_twoway $treeH $treeM; then false; else :; fi'
+test_expect_success '22 - local change cache updated.' '
+	rm -f .git/index &&
+	read_tree_must_succeed $treeH &&
+	git checkout-index -u -f -q -a &&
+	sed -e "s/such as/SUCH AS/" bozbar-old >bozbar &&
+	git update-index --add bozbar &&
+	if read_tree_twoway $treeH $treeM; then false; else :; fi
+'
 
 # Also make sure we did not break DF vs DF/DF case.
-test_expect_success \
-    'DF vs DF/DF case setup.' \
-    'rm -f .git/index &&
-     echo DF >DF &&
-     git update-index --add DF &&
-     treeDF=$(git write-tree) &&
-     echo treeDF $treeDF &&
-     git ls-tree $treeDF &&
-
-     rm -f DF &&
-     mkdir DF &&
-     echo DF/DF >DF/DF &&
-     git update-index --add --remove DF DF/DF &&
-     treeDFDF=$(git write-tree) &&
-     echo treeDFDF $treeDFDF &&
-     git ls-tree $treeDFDF &&
-     git ls-files --stage >DFDF.out'
-
-test_expect_success \
-    'DF vs DF/DF case test.' \
-    'rm -f .git/index &&
-     rm -fr DF &&
-     echo DF >DF &&
-     git update-index --add DF &&
-     read_tree_twoway $treeDF $treeDFDF &&
-     git ls-files --stage >DFDFcheck.out &&
-     test_cmp DFDF.out DFDFcheck.out &&
-     check_cache_at DF/DF dirty &&
-     :'
-
-test_expect_success \
-    'a/b (untracked) vs a case setup.' \
-    'rm -f .git/index &&
-     : >a &&
-     git update-index --add a &&
-     treeM=$(git write-tree) &&
-     echo treeM $treeM &&
-     git ls-tree $treeM &&
-     git ls-files --stage >treeM.out &&
-
-     rm -f a &&
-     git update-index --remove a &&
-     mkdir a &&
-     : >a/b &&
-     treeH=$(git write-tree) &&
-     echo treeH $treeH &&
-     git ls-tree $treeH'
-
-test_expect_success \
-    'a/b (untracked) vs a, plus c/d case test.' \
-    'read_tree_u_must_fail -u -m "$treeH" "$treeM" &&
-     git ls-files --stage &&
-     test -f a/b'
-
-test_expect_success \
-    'a/b vs a, plus c/d case setup.' \
-    'rm -f .git/index &&
-     rm -fr a &&
-     : >a &&
-     mkdir c &&
-     : >c/d &&
-     git update-index --add a c/d &&
-     treeM=$(git write-tree) &&
-     echo treeM $treeM &&
-     git ls-tree $treeM &&
-     git ls-files --stage >treeM.out &&
-
-     rm -f a &&
-     mkdir a &&
-     : >a/b &&
-     git update-index --add --remove a a/b &&
-     treeH=$(git write-tree) &&
-     echo treeH $treeH &&
-     git ls-tree $treeH'
-
-test_expect_success \
-    'a/b vs a, plus c/d case test.' \
-    'read_tree_u_must_succeed -u -m "$treeH" "$treeM" &&
-     git ls-files --stage | tee >treeMcheck.out &&
-     test_cmp treeM.out treeMcheck.out'
+test_expect_success 'DF vs DF/DF case setup.' '
+	rm -f .git/index &&
+	echo DF >DF &&
+	git update-index --add DF &&
+	treeDF=$(git write-tree) &&
+	echo treeDF $treeDF &&
+	git ls-tree $treeDF &&
+
+	rm -f DF &&
+	mkdir DF &&
+	echo DF/DF >DF/DF &&
+	git update-index --add --remove DF DF/DF &&
+	treeDFDF=$(git write-tree) &&
+	echo treeDFDF $treeDFDF &&
+	git ls-tree $treeDFDF &&
+	git ls-files --stage >DFDF.out
+'
+
+test_expect_success 'DF vs DF/DF case test.' '
+	rm -f .git/index &&
+	rm -fr DF &&
+	echo DF >DF &&
+	git update-index --add DF &&
+	read_tree_twoway $treeDF $treeDFDF &&
+	git ls-files --stage >DFDFcheck.out &&
+	test_cmp DFDF.out DFDFcheck.out &&
+	check_cache_at DF/DF dirty &&
+	:
+'
+
+test_expect_success 'a/b (untracked) vs a case setup.' '
+	rm -f .git/index &&
+	: >a &&
+	git update-index --add a &&
+	treeM=$(git write-tree) &&
+	echo treeM $treeM &&
+	git ls-tree $treeM &&
+	git ls-files --stage >treeM.out &&
+
+	rm -f a &&
+	git update-index --remove a &&
+	mkdir a &&
+	: >a/b &&
+	treeH=$(git write-tree) &&
+	echo treeH $treeH &&
+	git ls-tree $treeH
+'
+
+test_expect_success 'a/b (untracked) vs a, plus c/d case test.' '
+	read_tree_u_must_fail -u -m "$treeH" "$treeM" &&
+	git ls-files --stage &&
+	test -f a/b
+'
+
+test_expect_success 'read-tree supports the super-prefix' '
+	cat <<-EOF >expect &&
+		error: Updating '\''fictional/a'\'' would lose untracked files in it
+	EOF
+	test_must_fail git --super-prefix fictional/ read-tree -u -m "$treeH" "$treeM" 2>actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'a/b vs a, plus c/d case setup.' '
+	rm -f .git/index &&
+	rm -fr a &&
+	: >a &&
+	mkdir c &&
+	: >c/d &&
+	git update-index --add a c/d &&
+	treeM=$(git write-tree) &&
+	echo treeM $treeM &&
+	git ls-tree $treeM &&
+	git ls-files --stage >treeM.out &&
+
+	rm -f a &&
+	mkdir a &&
+	: >a/b &&
+	git update-index --add --remove a a/b &&
+	treeH=$(git write-tree) &&
+	echo treeH $treeH &&
+	git ls-tree $treeH
+'
+
+test_expect_success 'a/b vs a, plus c/d case test.' '
+	read_tree_u_must_succeed -u -m "$treeH" "$treeM" &&
+	git ls-files --stage | tee >treeMcheck.out &&
+	test_cmp treeM.out treeMcheck.out
+'
 
 test_expect_success '-m references the correct modified tree' '
 	echo >file-a &&
diff --git a/unpack-trees.c b/unpack-trees.c
index 129d49ff45..3a8ee19fe8 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -52,6 +52,41 @@ static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	  ? ((o)->msgs[(type)])      \
 	  : (unpack_plumbing_errors[(type)]) )
 
+static const char *super_prefixed(const char *path)
+{
+	/*
+	 * It is necessary and sufficient to have two static buffers
+	 * here, as the return value of this function is fed to
+	 * error() using the unpack_*_errors[] templates we see above.
+	 */
+	static struct strbuf buf[2] = {STRBUF_INIT, STRBUF_INIT};
+	static int super_prefix_len = -1;
+	static unsigned idx = ARRAY_SIZE(buf) - 1;
+
+	if (super_prefix_len < 0) {
+		const char *super_prefix = get_super_prefix();
+		if (!super_prefix) {
+			super_prefix_len = 0;
+		} else {
+			int i;
+			for (i = 0; i < ARRAY_SIZE(buf); i++)
+				strbuf_addstr(&buf[i], super_prefix);
+			super_prefix_len = buf[0].len;
+		}
+	}
+
+	if (!super_prefix_len)
+		return path;
+
+	if (++idx >= ARRAY_SIZE(buf))
+		idx = 0;
+
+	strbuf_setlen(&buf[idx], super_prefix_len);
+	strbuf_addstr(&buf[idx], path);
+
+	return buf[idx].buf;
+}
+
 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
 				  const char *cmd)
 {
@@ -172,7 +207,7 @@ static int add_rejected_path(struct unpack_trees_options *o,
 			     const char *path)
 {
 	if (!o->show_all_errors)
-		return error(ERRORMSG(o, e), path);
+		return error(ERRORMSG(o, e), super_prefixed(path));
 
 	/*
 	 * Otherwise, insert in a list for future display by
@@ -196,7 +231,7 @@ static void display_error_msgs(struct unpack_trees_options *o)
 			something_displayed = 1;
 			for (i = 0; i < rejects->nr; i++)
 				strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
-			error(ERRORMSG(o, e), path.buf);
+			error(ERRORMSG(o, e), super_prefixed(path.buf));
 			strbuf_release(&path);
 		}
 		string_list_clear(rejects, 0);
@@ -1925,7 +1960,9 @@ int bind_merge(const struct cache_entry * const *src,
 			     o->merge_size);
 	if (a && old)
 		return o->gently ? -1 :
-			error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
+			error(ERRORMSG(o, ERROR_BIND_OVERLAP),
+			      super_prefixed(a->name),
+			      super_prefixed(old->name));
 	if (!a)
 		return keep_entry(old, o);
 	else