diff --git a/t/.gitattributes b/t/.gitattributes
index df05434d32..dafa17c3e6 100644
--- a/t/.gitattributes
+++ b/t/.gitattributes
@@ -1,13 +1,13 @@
 t[0-9][0-9][0-9][0-9]/* -whitespace
 /chainlint/*.expect eol=lf
-/diff-lib/* eol=lf
+/lib-diff/* eol=lf
 /t0110/url-* binary
 /t3206/* eol=lf
 /t3900/*.txt eol=lf
 /t3901/*.txt eol=lf
-/t4034/*/* eol=lf
 /t4013/* eol=lf
 /t4018/* eol=lf
+/t4034/*/* eol=lf
 /t4051/* eol=lf
 /t4100/* eol=lf
 /t4101/* eol=lf
diff --git a/t/README b/t/README
index bc57006c04..593d4a4e27 100644
--- a/t/README
+++ b/t/README
@@ -917,13 +917,13 @@ library for your script to use.
 
    Check whether a file has the length it is expected to.
 
- - test_path_is_file <path> [<diagnosis>]
-   test_path_is_dir <path> [<diagnosis>]
-   test_path_is_missing <path> [<diagnosis>]
+ - test_path_is_file <path>
+   test_path_is_dir <path>
+   test_path_is_missing <path>
 
    Check if the named path is a file, if the named path is a
    directory, or if the named path does not exist, respectively,
-   and fail otherwise, showing the <diagnosis> text.
+   and fail otherwise.
 
  - test_when_finished <script>
 
diff --git a/t/lib-bitmap.sh b/t/lib-bitmap.sh
new file mode 100644
index 0000000000..fe3f98be24
--- /dev/null
+++ b/t/lib-bitmap.sh
@@ -0,0 +1,26 @@
+# Compare a file containing rev-list bitmap traversal output to its non-bitmap
+# counterpart. You can't just use test_cmp for this, because the two produce
+# subtly different output:
+#
+#   - regular output is in traversal order, whereas bitmap is split by type,
+#     with non-packed objects at the end
+#
+#   - regular output has a space and the pathname appended to non-commit
+#     objects; bitmap output omits this
+#
+# This function normalizes and compares the two. The second file should
+# always be the bitmap output.
+test_bitmap_traversal () {
+	if test "$1" = "--no-confirm-bitmaps"
+	then
+		shift
+	elif cmp "$1" "$2"
+	then
+		echo >&2 "identical raw outputs; are you sure bitmaps were used?"
+		return 1
+	fi &&
+	cut -d' ' -f1 "$1" | sort >"$1.normalized" &&
+	sort "$2" >"$2.normalized" &&
+	test_cmp "$1.normalized" "$2.normalized" &&
+	rm -f "$1.normalized" "$2.normalized"
+}
diff --git a/t/test-bundle-functions.sh b/t/lib-bundle.sh
similarity index 100%
rename from t/test-bundle-functions.sh
rename to t/lib-bundle.sh
diff --git a/t/diff-lib.sh b/t/lib-diff.sh
similarity index 100%
rename from t/diff-lib.sh
rename to t/lib-diff.sh
diff --git a/t/diff-lib/COPYING b/t/lib-diff/COPYING
similarity index 100%
rename from t/diff-lib/COPYING
rename to t/lib-diff/COPYING
diff --git a/t/diff-lib/README b/t/lib-diff/README
similarity index 100%
rename from t/diff-lib/README
rename to t/lib-diff/README
diff --git a/t/gitweb-lib.sh b/t/lib-gitweb.sh
similarity index 100%
rename from t/gitweb-lib.sh
rename to t/lib-gitweb.sh
diff --git a/t/t2104-update-index-skip-worktree.sh b/t/t2104-update-index-skip-worktree.sh
index 7e2e7dd4ae..30666fc70d 100755
--- a/t/t2104-update-index-skip-worktree.sh
+++ b/t/t2104-update-index-skip-worktree.sh
@@ -9,6 +9,11 @@ test_description='skip-worktree bit test'
 
 sane_unset GIT_TEST_SPLIT_INDEX
 
+test_set_index_version () {
+    GIT_INDEX_VERSION="$1"
+    export GIT_INDEX_VERSION
+}
+
 test_set_index_version 3
 
 cat >expect.full <<EOF
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 1e738df81d..28c2d15d80 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -101,7 +101,8 @@ test_expect_success 'rebase -i with the exec command' '
 	) &&
 	test_path_is_file touch-one &&
 	test_path_is_file touch-two &&
-	test_path_is_missing touch-three " (should have stopped before)" &&
+	# Missing because we should have stopped by now.
+	test_path_is_missing touch-three &&
 	test_cmp_rev C HEAD &&
 	git rebase --continue &&
 	test_path_is_file touch-three &&
diff --git a/t/t4000-diff-format.sh b/t/t4000-diff-format.sh
index e5116a76a1..cce334981e 100755
--- a/t/t4000-diff-format.sh
+++ b/t/t4000-diff-format.sh
@@ -7,7 +7,7 @@ test_description='Test built-in diff output engine.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 echo >path0 'Line 1
 Line 2
diff --git a/t/t4001-diff-rename.sh b/t/t4001-diff-rename.sh
index c16486a9d4..2f9700742a 100755
--- a/t/t4001-diff-rename.sh
+++ b/t/t4001-diff-rename.sh
@@ -7,7 +7,7 @@ test_description='Test rename detection in diff engine.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 test_expect_success 'setup' '
 	cat >path0 <<-\EOF &&
diff --git a/t/t4003-diff-rename-1.sh b/t/t4003-diff-rename-1.sh
index df2accb655..db07ff3eb1 100755
--- a/t/t4003-diff-rename-1.sh
+++ b/t/t4003-diff-rename-1.sh
@@ -7,11 +7,11 @@ test_description='More rename detection
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 test_expect_success \
     'prepare reference tree' \
-    'cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
+    'cat "$TEST_DIRECTORY"/lib-diff/COPYING >COPYING &&
      echo frotz >rezrov &&
     git update-index --add COPYING rezrov &&
     tree=$(git write-tree) &&
@@ -99,7 +99,7 @@ test_expect_success \
 
 test_expect_success \
     'prepare work tree once again' \
-    'cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
+    'cat "$TEST_DIRECTORY"/lib-diff/COPYING >COPYING &&
      git update-index --add --remove COPYING COPYING.1'
 
 # tree has COPYING and rezrov.  work tree has COPYING and COPYING.1,
diff --git a/t/t4004-diff-rename-symlink.sh b/t/t4004-diff-rename-symlink.sh
index 6e562c80d1..3d495e37bb 100755
--- a/t/t4004-diff-rename-symlink.sh
+++ b/t/t4004-diff-rename-symlink.sh
@@ -10,7 +10,7 @@ copy of symbolic links, but should not produce rename/copy followed
 by an edit for them.
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 test_expect_success SYMLINKS \
     'prepare reference tree' \
diff --git a/t/t4005-diff-rename-2.sh b/t/t4005-diff-rename-2.sh
index d18a80493c..8647906132 100755
--- a/t/t4005-diff-rename-2.sh
+++ b/t/t4005-diff-rename-2.sh
@@ -6,10 +6,10 @@
 test_description='Same rename detection as t4003 but testing diff-raw.'
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 test_expect_success 'setup reference tree' '
-	cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
+	cat "$TEST_DIRECTORY"/lib-diff/COPYING >COPYING &&
 	echo frotz >rezrov &&
 	git update-index --add COPYING rezrov &&
 	tree=$(git write-tree) &&
@@ -64,7 +64,7 @@ test_expect_success 'validate output from rename/copy detection (#2)' '
 # nows how to say Copy.
 
 test_expect_success 'validate output from rename/copy detection (#3)' '
-	cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
+	cat "$TEST_DIRECTORY"/lib-diff/COPYING >COPYING &&
 	git update-index --add --remove COPYING COPYING.1 &&
 
 	cat <<-EOF >expected &&
diff --git a/t/t4007-rename-3.sh b/t/t4007-rename-3.sh
index b187b7f6c6..cbb9c62f53 100755
--- a/t/t4007-rename-3.sh
+++ b/t/t4007-rename-3.sh
@@ -7,17 +7,17 @@ test_description='Rename interaction with pathspec.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 test_expect_success 'prepare reference tree' '
 	mkdir path0 path1 &&
-	cp "$TEST_DIRECTORY"/diff-lib/COPYING path0/COPYING &&
+	cp "$TEST_DIRECTORY"/lib-diff/COPYING path0/COPYING &&
 	git update-index --add path0/COPYING &&
 	tree=$(git write-tree) &&
 	echo $tree
 '
 
-blob=$(git hash-object "$TEST_DIRECTORY/diff-lib/COPYING")
+blob=$(git hash-object "$TEST_DIRECTORY/lib-diff/COPYING")
 test_expect_success 'prepare work tree' '
 	cp path0/COPYING path1/COPYING &&
 	git update-index --add --remove path0/COPYING path1/COPYING
diff --git a/t/t4008-diff-break-rewrite.sh b/t/t4008-diff-break-rewrite.sh
index b1ccd4102e..2299f27511 100755
--- a/t/t4008-diff-break-rewrite.sh
+++ b/t/t4008-diff-break-rewrite.sh
@@ -22,11 +22,11 @@ With -B, this should be detected as two complete rewrites.
 Further, with -B and -M together, these should turn into two renames.
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 test_expect_success setup '
-	cat "$TEST_DIRECTORY"/diff-lib/README >file0 &&
-	cat "$TEST_DIRECTORY"/diff-lib/COPYING >file1 &&
+	cat "$TEST_DIRECTORY"/lib-diff/README >file0 &&
+	cat "$TEST_DIRECTORY"/lib-diff/COPYING >file1 &&
 	blob0_id=$(git hash-object file0) &&
 	blob1_id=$(git hash-object file1) &&
 	git update-index --add file0 file1 &&
diff --git a/t/t4009-diff-rename-4.sh b/t/t4009-diff-rename-4.sh
index b63bdf031f..b1da807f16 100755
--- a/t/t4009-diff-rename-4.sh
+++ b/t/t4009-diff-rename-4.sh
@@ -7,11 +7,11 @@ test_description='Same rename detection as t4003 but testing diff-raw -z.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 test_expect_success \
     'prepare reference tree' \
-    'cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
+    'cat "$TEST_DIRECTORY"/lib-diff/COPYING >COPYING &&
      echo frotz >rezrov &&
     git update-index --add COPYING rezrov &&
     orig=$(git hash-object COPYING) &&
@@ -81,7 +81,7 @@ test_expect_success \
 
 test_expect_success \
     'prepare work tree once again' \
-    'cat "$TEST_DIRECTORY"/diff-lib/COPYING >COPYING &&
+    'cat "$TEST_DIRECTORY"/lib-diff/COPYING >COPYING &&
      git update-index --add --remove COPYING COPYING.1'
 
 git diff-index -z -C --find-copies-harder $tree >current
diff --git a/t/t4010-diff-pathspec.sh b/t/t4010-diff-pathspec.sh
index 65cc703c65..1bbced79ec 100755
--- a/t/t4010-diff-pathspec.sh
+++ b/t/t4010-diff-pathspec.sh
@@ -10,7 +10,7 @@ Prepare:
         path1/file1
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 test_expect_success \
     setup \
diff --git a/t/t4011-diff-symlink.sh b/t/t4011-diff-symlink.sh
index 717034bb50..5a25c259fe 100755
--- a/t/t4011-diff-symlink.sh
+++ b/t/t4011-diff-symlink.sh
@@ -7,7 +7,7 @@ test_description='Test diff of symlinks.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 # Print the short OID of a symlink with the given name.
 symlink_oid () {
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index ce6aa3914f..fcc30d8cc2 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -9,7 +9,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 test_expect_success setup '
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 8c574221b2..2c13b62d3c 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -7,7 +7,7 @@ test_description='Test special whitespace in diff engine.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 test_expect_success "Ray Lehtiniemi's example" '
 	cat <<-\EOF >x &&
diff --git a/t/t4027-diff-submodule.sh b/t/t4027-diff-submodule.sh
index 894a11b224..94ef77e1df 100755
--- a/t/t4027-diff-submodule.sh
+++ b/t/t4027-diff-submodule.sh
@@ -3,7 +3,7 @@
 test_description='difference in submodules'
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 test_expect_success setup '
 	test_tick &&
diff --git a/t/t4034-diff-words.sh b/t/t4034-diff-words.sh
index 0c8fb39ced..56f1e62a97 100755
--- a/t/t4034-diff-words.sh
+++ b/t/t4034-diff-words.sh
@@ -3,7 +3,7 @@
 test_description='word diff colors'
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 cat >pre.simple <<-\EOF
 	h(4)
diff --git a/t/t4038-diff-combined.sh b/t/t4038-diff-combined.sh
index 09ad491a59..aeac203c42 100755
--- a/t/t4038-diff-combined.sh
+++ b/t/t4038-diff-combined.sh
@@ -6,7 +6,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 setup_helper () {
 	one=$1 branch=$2 side=$3 &&
diff --git a/t/t4061-diff-indent.sh b/t/t4061-diff-indent.sh
index bcf7493740..7750b87ca1 100755
--- a/t/t4061-diff-indent.sh
+++ b/t/t4061-diff-indent.sh
@@ -7,7 +7,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 # Compare two diff outputs. Ignore "index" lines, because we don't
 # care about SHA-1s or file modes.
diff --git a/t/t4206-log-follow-harder-copies.sh b/t/t4206-log-follow-harder-copies.sh
index ad29e65fcb..4871a5dc92 100755
--- a/t/t4206-log-follow-harder-copies.sh
+++ b/t/t4206-log-follow-harder-copies.sh
@@ -7,7 +7,7 @@ test_description='Test --follow should always find copies hard in git log.
 
 '
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 echo >path0 'Line 1
 Line 2
diff --git a/t/t5310-pack-bitmaps.sh b/t/t5310-pack-bitmaps.sh
index 5ba7603109..40b9f63244 100755
--- a/t/t5310-pack-bitmaps.sh
+++ b/t/t5310-pack-bitmaps.sh
@@ -5,6 +5,8 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-bundle.sh
+. "$TEST_DIRECTORY"/lib-bitmap.sh
 
 objpath () {
 	echo ".git/objects/$(echo "$1" | sed -e 's|\(..\)|\1/|')"
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 5b15f1aa0f..fa2ba93fe8 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -551,7 +551,7 @@ corrupt_graph_and_verify() {
 	zero_pos=${4:-${orig_size}} &&
 	printf "$data" | dd of="$objdir/info/commit-graph" bs=1 seek="$pos" conv=notrunc &&
 	dd of="$objdir/info/commit-graph" bs=1 seek="$zero_pos" if=/dev/null &&
-	generate_zero_bytes $(($orig_size - $zero_pos)) >>"$objdir/info/commit-graph" &&
+	test-tool genzeros $(($orig_size - $zero_pos)) >>"$objdir/info/commit-graph" &&
 	corrupt_graph_verify "$grepstr"
 
 }
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index 42f5503004..c1e0eb3923 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -9,7 +9,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/test-bundle-functions.sh
+. "$TEST_DIRECTORY"/lib-bundle.sh
 
 D=$(pwd)
 
diff --git a/t/t6020-bundle-misc.sh b/t/t6020-bundle-misc.sh
index 6249420a80..da5fe1ba6d 100755
--- a/t/t6020-bundle-misc.sh
+++ b/t/t6020-bundle-misc.sh
@@ -9,7 +9,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/test-bundle-functions.sh
+. "$TEST_DIRECTORY"/lib-bundle.sh
 
 # Create a commit or tag and set the variable with the object ID.
 test_commit_setvar () {
diff --git a/t/t6113-rev-list-bitmap-filters.sh b/t/t6113-rev-list-bitmap-filters.sh
index 2b551e6fd0..3f889949ca 100755
--- a/t/t6113-rev-list-bitmap-filters.sh
+++ b/t/t6113-rev-list-bitmap-filters.sh
@@ -2,6 +2,7 @@
 
 test_description='rev-list combining bitmaps and filters'
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-bitmap.sh
 
 test_expect_success 'set up bitmapped repo' '
 	# one commit will have bitmaps, the other will not
diff --git a/t/t6426-merge-skip-unneeded-updates.sh b/t/t6426-merge-skip-unneeded-updates.sh
index d7eeee4310..7b5f1c1dcd 100755
--- a/t/t6426-merge-skip-unneeded-updates.sh
+++ b/t/t6426-merge-skip-unneeded-updates.sh
@@ -492,7 +492,9 @@ test_expect_success '3a-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 		test_cmp expect actual &&
 
 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
-		test_path_is_missing bq foo/bq foo/whatever
+		test_path_is_missing bq &&
+		test_path_is_missing foo/bq &&
+		test_path_is_missing foo/whatever
 	)
 '
 
@@ -522,7 +524,9 @@ test_expect_success '3a-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 		test_cmp expect actual &&
 
 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
-		test_path_is_missing bq foo/bq foo/whatever
+		test_path_is_missing bq &&
+		test_path_is_missing foo/bq &&
+		test_path_is_missing foo/whatever
 	)
 '
 
@@ -588,7 +592,9 @@ test_expect_success '3b-L: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 		test_cmp expect actual &&
 
 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
-		test_path_is_missing bq foo/bq foo/whatever
+		test_path_is_missing bq &&
+		test_path_is_missing foo/bq &&
+		test_path_is_missing foo/whatever
 	)
 '
 
@@ -618,7 +624,9 @@ test_expect_success '3b-R: bq_1->foo/bq_2 on A, foo/->bar/ on B' '
 		test_cmp expect actual &&
 
 		test_must_fail git rev-parse HEAD:bq HEAD:foo/bq &&
-		test_path_is_missing bq foo/bq foo/whatever
+		test_path_is_missing bq &&
+		test_path_is_missing foo/bq &&
+		test_path_is_missing foo/whatever
 	)
 '
 
diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index f76586f808..60d961b526 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -78,7 +78,7 @@ test_expect_success 'gc --keep-largest-pack' '
 		git gc &&
 		( cd .git/objects/pack && ls *.pack ) >pack-list &&
 		test_line_count = 1 pack-list &&
-		BASE_PACK=.git/objects/pack/pack-*.pack &&
+		cp pack-list base-pack-list &&
 		test_commit four &&
 		git repack -d &&
 		test_commit five &&
@@ -90,7 +90,7 @@ test_expect_success 'gc --keep-largest-pack' '
 		test_line_count = 2 pack-list &&
 		awk "/^P /{print \$2}" <.git/objects/info/packs >pack-info &&
 		test_line_count = 2 pack-info &&
-		test_path_is_file $BASE_PACK &&
+		test_path_is_file .git/objects/pack/$(cat base-pack-list) &&
 		git fsck
 	)
 '
diff --git a/t/t7501-commit-basic-functionality.sh b/t/t7501-commit-basic-functionality.sh
index 0f936182e4..512ae2781f 100755
--- a/t/t7501-commit-basic-functionality.sh
+++ b/t/t7501-commit-basic-functionality.sh
@@ -11,7 +11,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY/diff-lib.sh"
+. "$TEST_DIRECTORY/lib-diff.sh"
 
 author='The Real Author <someguy@his.email.org>'
 
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 8f1caf8025..5c47ac4465 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -8,7 +8,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/diff-lib.sh ;# test-lib chdir's into trash
+. "$TEST_DIRECTORY"/lib-diff.sh ;# test-lib chdir's into trash
 
 verify_packs () {
 	for p in .git/objects/pack/*.pack
diff --git a/t/t9500-gitweb-standalone-no-errors.sh b/t/t9500-gitweb-standalone-no-errors.sh
index ee8c6e30e6..0333065d4d 100755
--- a/t/t9500-gitweb-standalone-no-errors.sh
+++ b/t/t9500-gitweb-standalone-no-errors.sh
@@ -13,7 +13,7 @@ or warnings to log.'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-. ./gitweb-lib.sh
+. ./lib-gitweb.sh
 
 # ----------------------------------------------------------------------
 # no commits (empty, just initialized repository)
diff --git a/t/t9501-gitweb-standalone-http-status.sh b/t/t9501-gitweb-standalone-http-status.sh
index 141610de54..32814e75df 100755
--- a/t/t9501-gitweb-standalone-http-status.sh
+++ b/t/t9501-gitweb-standalone-http-status.sh
@@ -13,7 +13,7 @@ code and message.'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-. ./gitweb-lib.sh
+. ./lib-gitweb.sh
 
 #
 # Gitweb only provides the functionality tested by the 'modification times'
diff --git a/t/t9502-gitweb-standalone-parse-output.sh b/t/t9502-gitweb-standalone-parse-output.sh
index 9cf7ab30a8..3167473b30 100755
--- a/t/t9502-gitweb-standalone-parse-output.sh
+++ b/t/t9502-gitweb-standalone-parse-output.sh
@@ -13,7 +13,7 @@ in the HTTP header or the actual script output.'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-. ./gitweb-lib.sh
+. ./lib-gitweb.sh
 
 # ----------------------------------------------------------------------
 # snapshot file name and prefix
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 05dc2cc6be..c96a555ace 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -32,11 +32,6 @@ test_set_editor () {
 	export EDITOR
 }
 
-test_set_index_version () {
-    GIT_INDEX_VERSION="$1"
-    export GIT_INDEX_VERSION
-}
-
 test_decode_color () {
 	awk '
 		function name(n) {
@@ -116,13 +111,6 @@ remove_cr () {
 	tr '\015' Q | sed -e 's/Q$//'
 }
 
-# Generate an output of $1 bytes of all zeroes (NULs, not ASCII zeroes).
-# If $1 is 'infinity', output forever or until the receiving pipe stops reading,
-# whichever comes first.
-generate_zero_bytes () {
-	test-tool genzeros "$@"
-}
-
 # In some bourne shell implementations, the "unset" builtin returns
 # nonzero status when a variable to be unset was not set in the first
 # place.
@@ -735,34 +723,37 @@ test_external_without_stderr () {
 }
 
 # debugging-friendly alternatives to "test [-f|-d|-e]"
-# The commands test the existence or non-existence of $1. $2 can be
-# given to provide a more precise diagnosis.
+# The commands test the existence or non-existence of $1
 test_path_is_file () {
+	test "$#" -ne 1 && BUG "1 param"
 	if ! test -f "$1"
 	then
-		echo "File $1 doesn't exist. $2"
+		echo "File $1 doesn't exist"
 		false
 	fi
 }
 
 test_path_is_dir () {
+	test "$#" -ne 1 && BUG "1 param"
 	if ! test -d "$1"
 	then
-		echo "Directory $1 doesn't exist. $2"
+		echo "Directory $1 doesn't exist"
 		false
 	fi
 }
 
 test_path_exists () {
+	test "$#" -ne 1 && BUG "1 param"
 	if ! test -e "$1"
 	then
-		echo "Path $1 doesn't exist. $2"
+		echo "Path $1 doesn't exist"
 		false
 	fi
 }
 
 # Check if the directory exists and is empty as expected, barf otherwise.
 test_dir_is_empty () {
+	test "$#" -ne 1 && BUG "1 param"
 	test_path_is_dir "$1" &&
 	if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')"
 	then
@@ -774,6 +765,7 @@ test_dir_is_empty () {
 
 # Check if the file exists and has a size greater than zero
 test_file_not_empty () {
+	test "$#" = 2 && BUG "2 param"
 	if ! test -s "$1"
 	then
 		echo "'$1' is not a non-empty file."
@@ -782,6 +774,7 @@ test_file_not_empty () {
 }
 
 test_path_is_missing () {
+	test "$#" -ne 1 && BUG "1 param"
 	if test -e "$1"
 	then
 		echo "Path exists:"
@@ -818,6 +811,7 @@ test_line_count () {
 }
 
 test_file_size () {
+	test "$#" -ne 1 && BUG "1 param"
 	test-tool path-utils file-size "$1"
 }
 
@@ -990,6 +984,7 @@ test_expect_code () {
 # - not all diff versions understand "-u"
 
 test_cmp () {
+	test "$#" -ne 2 && BUG "2 param"
 	eval "$GIT_TEST_CMP" '"$@"'
 }
 
@@ -1019,6 +1014,7 @@ test_cmp_config () {
 # test_cmp_bin - helper to compare binary files
 
 test_cmp_bin () {
+	test "$#" -ne 2 && BUG "2 param"
 	cmp "$@"
 }
 
@@ -1079,6 +1075,7 @@ verbose () {
 # otherwise.
 
 test_must_be_empty () {
+	test "$#" -ne 1 && BUG "1 param"
 	test_path_is_file "$1" &&
 	if test -s "$1"
 	then
@@ -1102,7 +1099,7 @@ test_cmp_rev () {
 	fi
 	if test $# != 2
 	then
-		error "bug in the test script: test_cmp_rev requires two revisions, but got $#"
+		BUG "test_cmp_rev requires two revisions, but got $#"
 	else
 		local r1 r2
 		r1=$(git rev-parse --verify "$1") &&
@@ -1213,7 +1210,7 @@ test_atexit () {
 	# doing so on Bash is better than nothing (the test will
 	# silently pass on other shells).
 	test "${BASH_SUBSHELL-0}" = 0 ||
-	error "bug in test script: test_atexit does nothing in a subshell"
+	BUG "test_atexit does nothing in a subshell"
 	test_atexit_cleanup="{ $*
 		} && (exit \"\$eval_ret\"); eval_ret=\$?; $test_atexit_cleanup"
 }
@@ -1611,33 +1608,6 @@ test_set_port () {
 	eval $var=$port
 }
 
-# Compare a file containing rev-list bitmap traversal output to its non-bitmap
-# counterpart. You can't just use test_cmp for this, because the two produce
-# subtly different output:
-#
-#   - regular output is in traversal order, whereas bitmap is split by type,
-#     with non-packed objects at the end
-#
-#   - regular output has a space and the pathname appended to non-commit
-#     objects; bitmap output omits this
-#
-# This function normalizes and compares the two. The second file should
-# always be the bitmap output.
-test_bitmap_traversal () {
-	if test "$1" = "--no-confirm-bitmaps"
-	then
-		shift
-	elif cmp "$1" "$2"
-	then
-		echo >&2 "identical raw outputs; are you sure bitmaps were used?"
-		return 1
-	fi &&
-	cut -d' ' -f1 "$1" | sort >"$1.normalized" &&
-	sort "$2" >"$2.normalized" &&
-	test_cmp "$1.normalized" "$2.normalized" &&
-	rm -f "$1.normalized" "$2.normalized"
-}
-
 # Tests for the hidden file attribute on Windows
 test_path_is_hidden () {
 	test_have_prereq MINGW ||
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 431adba0fb..987a6c1936 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -453,36 +453,6 @@ export GIT_DEFAULT_HASH
 GIT_TRACE_BARE=1
 export GIT_TRACE_BARE
 
-check_var_migration () {
-	# the warnings and hints given from this helper depends
-	# on end-user settings, which will disrupt the self-test
-	# done on the test framework itself.
-	case "$GIT_TEST_FRAMEWORK_SELFTEST" in
-	t)	return ;;
-	esac
-
-	old_name=$1 new_name=$2
-	eval "old_isset=\${${old_name}:+isset}"
-	eval "new_isset=\${${new_name}:+isset}"
-
-	case "$old_isset,$new_isset" in
-	isset,)
-		echo >&2 "warning: $old_name is now $new_name"
-		echo >&2 "hint: set $new_name too during the transition period"
-		eval "$new_name=\$$old_name"
-		;;
-	isset,isset)
-		# do this later
-		# echo >&2 "warning: $old_name is now $new_name"
-		# echo >&2 "hint: remove $old_name"
-		;;
-	esac
-}
-
-check_var_migration GIT_FSMONITOR_TEST GIT_TEST_FSMONITOR
-check_var_migration TEST_GIT_INDEX_VERSION GIT_TEST_INDEX_VERSION
-check_var_migration GIT_FORCE_PRELOAD_TEST GIT_TEST_PRELOAD_INDEX
-
 # Use specific version of the index file format
 if test -n "${GIT_TEST_INDEX_VERSION:+isset}"
 then