24 files changed, 319 insertions, 118 deletions

diff --git a/.github/workflows/check-whitespace.yml b/.github/workflows/check-whitespace.yml
index ad3466a..a58e2dc 100644
--- a/.github/workflows/check-whitespace.yml
+++ b/.github/workflows/check-whitespace.yml
@@ -9,42 +9,83 @@ on:
   pull_request:
     types: [opened, synchronize]
 
+# Avoid unnecessary builds. Unlike the main CI jobs, these are not
+# ci-configurable (but could be).
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   check-whitespace:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         fetch-depth: 0
 
     - name: git log --check
       id: check_out
       run: |
-        log=
+        baseSha=${{github.event.pull_request.base.sha}}
+        problems=()
         commit=
-        while read dash etc
+        commitText=
+        commitTextmd=
+        goodparent=
+        while read dash sha etc
         do
           case "${dash}" in
           "---")
-            commit="${etc}"
+            if test -z "${commit}"
+            then
+              goodparent=${sha}
+            fi
+            commit="${sha}"
+            commitText="${sha} ${etc}"
+            commitTextmd="[${sha}](https://github.com/${{ github.repository }}/commit/${sha}) ${etc}"
             ;;
           "")
             ;;
           *)
             if test -n "${commit}"
             then
-              log="${log}\n${commit}"
+              problems+=("1) --- ${commitTextmd}")
               echo ""
-              echo "--- ${commit}"
+              echo "--- ${commitText}"
+              commit=
             fi
-            commit=
-            log="${log}\n${dash} ${etc}"
-            echo "${dash} ${etc}"
+            case "${dash}" in
+            *:[1-9]*:) # contains file and line number information
+              dashend=${dash#*:}
+              problems+=("[${dash}](https://github.com/${{ github.repository }}/blob/${{github.event.pull_request.head.ref}}/${dash%%:*}#L${dashend%:}) ${sha} ${etc}")
+              ;;
+            *)
+              problems+=("\`${dash} ${sha} ${etc}\`")
+              ;;
+            esac
+            echo "${dash} ${sha} ${etc}"
             ;;
           esac
-        done <<< $(git log --check --pretty=format:"---% h% s" ${{github.event.pull_request.base.sha}}..)
+        done <<< $(git log --check --pretty=format:"---% h% s" ${baseSha}..)
 
-        if test -n "${log}"
+        if test ${#problems[*]} -gt 0
         then
+          if test -z "${commit}"
+          then
+            goodparent=${baseSha: 0:7}
+          fi
+          echo "🛑 Please review the Summary output for further information."
+          echo "### :x: A whitespace issue was found in one or more of the commits." >$GITHUB_STEP_SUMMARY
+          echo "" >>$GITHUB_STEP_SUMMARY
+          echo "Run these commands to correct the problem:" >>$GITHUB_STEP_SUMMARY
+          echo "1. \`git rebase --whitespace=fix ${goodparent}\`" >>$GITHUB_STEP_SUMMARY
+          echo "1. \`git push --force\`" >>$GITHUB_STEP_SUMMARY
+          echo " " >>$GITHUB_STEP_SUMMARY
+          echo "Errors:" >>$GITHUB_STEP_SUMMARY
+          for i in "${problems[@]}"
+          do
+            echo "${i}" >>$GITHUB_STEP_SUMMARY
+          done
+
           exit 2
         fi
diff --git a/.github/workflows/l10n.yml b/.github/workflows/l10n.yml
index f7ea0f0..6c38496 100644
--- a/.github/workflows/l10n.yml
+++ b/.github/workflows/l10n.yml
@@ -2,6 +2,12 @@ name: git-l10n
 
 on: [push, pull_request_target]
 
+# Avoid unnecessary builds. Unlike the main CI jobs, these are not
+# ci-configurable (but could be).
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   git-po-helper:
     if: >-
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index e67847a..30492ea 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -11,6 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       enabled: ${{ steps.check-ref.outputs.enabled }}${{ steps.skip-if-redundant.outputs.enabled }}
+      skip_concurrent: ${{ steps.check-ref.outputs.skip_concurrent }}
     steps:
       - name: try to clone ci-config branch
         run: |
@@ -34,7 +35,15 @@ jobs:
           then
             enabled=no
           fi
+
+          skip_concurrent=yes
+          if test -x config-repo/ci/config/skip-concurrent &&
+             ! config-repo/ci/config/skip-concurrent '${{ github.ref }}'
+          then
+            skip_concurrent=no
+          fi
           echo "enabled=$enabled" >>$GITHUB_OUTPUT
+          echo "skip_concurrent=$skip_concurrent" >>$GITHUB_OUTPUT
       - name: skip if the commit or tree was already tested
         id: skip-if-redundant
         uses: actions/github-script@v6
@@ -82,6 +91,9 @@ jobs:
     needs: ci-config
     if: needs.ci-config.outputs.enabled == 'yes'
     runs-on: windows-latest
+    concurrency:
+      group: windows-build-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: actions/checkout@v3
     - uses: git-for-windows/setup-git-for-windows-sdk@v1
@@ -101,11 +113,14 @@ jobs:
   windows-test:
     name: win test
     runs-on: windows-latest
-    needs: [windows-build]
+    needs: [ci-config, windows-build]
     strategy:
       fail-fast: false
       matrix:
         nr: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    concurrency:
+      group: windows-test-${{ matrix.nr }}-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - name: download tracked files and build artifacts
       uses: actions/download-artifact@v3
@@ -132,11 +147,14 @@ jobs:
   vs-build:
     name: win+VS build
     needs: ci-config
-    if: needs.ci-config.outputs.enabled == 'yes'
+    if: github.event.repository.owner.login == 'git-for-windows' && needs.ci-config.outputs.enabled == 'yes'
     env:
       NO_PERL: 1
       GIT_CONFIG_PARAMETERS: "'user.name=CI' 'user.email=ci@git'"
     runs-on: windows-latest
+    concurrency:
+      group: vs-build-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: actions/checkout@v3
     - uses: git-for-windows/setup-git-for-windows-sdk@v1
@@ -184,11 +202,14 @@ jobs:
   vs-test:
     name: win+VS test
     runs-on: windows-latest
-    needs: vs-build
+    needs: [ci-config, vs-build]
     strategy:
       fail-fast: false
       matrix:
         nr: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+    concurrency:
+      group: vs-test-${{ matrix.nr }}-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: git-for-windows/setup-git-for-windows-sdk@v1
     - name: download tracked files and build artifacts
@@ -218,6 +239,9 @@ jobs:
     name: ${{matrix.vector.jobname}} (${{matrix.vector.pool}})
     needs: ci-config
     if: needs.ci-config.outputs.enabled == 'yes'
+    concurrency:
+      group: ${{ matrix.vector.jobname }}-${{ matrix.vector.pool }}-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     strategy:
       fail-fast: false
       matrix:
@@ -265,8 +289,9 @@ jobs:
     - uses: actions/checkout@v3
     - run: ci/install-dependencies.sh
     - run: ci/run-build-and-tests.sh
-    - run: ci/print-test-failures.sh
+    - name: print test failures
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
+      run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
       uses: actions/upload-artifact@v3
@@ -277,6 +302,9 @@ jobs:
     name: ${{matrix.vector.jobname}} (${{matrix.vector.image}})
     needs: ci-config
     if: needs.ci-config.outputs.enabled == 'yes'
+    concurrency:
+      group: dockerized-${{ matrix.vector.jobname }}-${{ matrix.vector.image }}-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     strategy:
       fail-fast: false
       matrix:
@@ -298,8 +326,9 @@ jobs:
       if: matrix.vector.jobname == 'linux32'
     - run: ci/install-docker-dependencies.sh
     - run: ci/run-build-and-tests.sh
-    - run: ci/print-test-failures.sh
+    - name: print test failures
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
+      run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != '' && matrix.vector.jobname != 'linux32'
       uses: actions/upload-artifact@v3
@@ -318,6 +347,9 @@ jobs:
     env:
       jobname: StaticAnalysis
     runs-on: ubuntu-22.04
+    concurrency:
+      group: static-analysis-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: actions/checkout@v3
     - run: ci/install-dependencies.sh
@@ -329,6 +361,9 @@ jobs:
     env:
       jobname: sparse
     runs-on: ubuntu-20.04
+    concurrency:
+      group: sparse-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - name: Download a current `sparse` package
       # Ubuntu's `sparse` version is too old for us
@@ -347,6 +382,9 @@ jobs:
     name: documentation
     needs: ci-config
     if: needs.ci-config.outputs.enabled == 'yes'
+    concurrency:
+      group: documentation-${{ github.ref }}
+      cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     env:
       jobname: Documentation
     runs-on: ubuntu-latest
diff --git a/Documentation/RelNotes/2.40.0.txt b/Documentation/RelNotes/2.40.0.txt
index 5193a99..d7685b8 100644
--- a/Documentation/RelNotes/2.40.0.txt
+++ b/Documentation/RelNotes/2.40.0.txt
@@ -48,6 +48,20 @@ Performance, Internal Implementation, Development Support etc.
  * Stop using "git --super-prefix" and narrow the scope of its use to
    the submodule--helper.
 
+ * Stop running win+VS build by default.
+   (merge a0da6deeec js/ci-disable-cmake-by-default later to maint).
+
+ * CI updates.  We probably want a clean-up to move the long shell
+   script embedded in yaml file into a separate file, but that can
+   come later.
+   (merge 4542582e59 cw/ci-whitespace later to maint).
+
+ * Use `git diff --no-index` as a test_cmp on Windows.
+
+   We'd probably need to revisit "do we really want to, and have to,
+   lose CRLF vs LF?" later, at which time we may be able to further
+   clean this up by replacing "git diff --no-index" with "diff -u".
+
 
 Fixes since v2.39
 -----------------
diff --git a/Documentation/config/feature.txt b/Documentation/config/feature.txt
index 95975e5..e52bc6b 100644
--- a/Documentation/config/feature.txt
+++ b/Documentation/config/feature.txt
@@ -23,6 +23,11 @@ feature.manyFiles::
 	working directory. With many files, commands such as `git status` and
 	`git checkout` may be slow and these new defaults improve performance:
 +
+* `index.skipHash=true` speeds up index writes by not computing a trailing
+  checksum. Note that this will cause Git versions earlier than 2.13.0 to
+  refuse to parse the index and Git versions earlier than 2.40.0 will report
+  a corrupted index during `git fsck`.
++
 * `index.version=4` enables path-prefix compression in the index.
 +
 * `core.untrackedCache=true` enables the untracked cache. This setting assumes
diff --git a/Documentation/config/index.txt b/Documentation/config/index.txt
index 75f3a2d..23c7985 100644
--- a/Documentation/config/index.txt
+++ b/Documentation/config/index.txt
@@ -30,3 +30,14 @@ index.version::
 	Specify the version with which new index files should be
 	initialized.  This does not affect existing repositories.
 	If `feature.manyFiles` is enabled, then the default is 4.
+
+index.skipHash::
+	When enabled, do not compute the trailing hash for the index file.
+	This accelerates Git commands that manipulate the index, such as
+	`git add`, `git commit`, or `git status`. Instead of storing the
+	checksum, write a trailing set of bytes with value zero, indicating
+	that the computation was skipped.
++
+If you enable `index.skipHash`, then Git clients older than 2.13.0 will
+refuse to parse the index and Git clients older than 2.40.0 will report an
+error during `git fsck`.
diff --git a/Documentation/git-am.txt b/Documentation/git-am.txt
index 326276e..0c1dfb3 100644
--- a/Documentation/git-am.txt
+++ b/Documentation/git-am.txt
@@ -9,7 +9,7 @@ git-am - Apply a series of patches from a mailbox
 SYNOPSIS
 --------
 [verse]
-'git am' [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8]
+'git am' [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8] [--no-verify]
 	 [--[no-]3way] [--interactive] [--committer-date-is-author-date]
 	 [--ignore-date] [--ignore-space-change | --ignore-whitespace]
 	 [--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
@@ -138,6 +138,12 @@ include::rerere-options.txt[]
 --interactive::
 	Run interactively.
 
+-n::
+--no-verify::
+	By default, the pre-applypatch and applypatch-msg hooks are run.
+	When any of `--no-verify` or `-n` is given, these are bypassed.
+	See also linkgit:githooks[5].
+
 --committer-date-is-author-date::
 	By default the command records the date from the e-mail
 	message as the commit author date, and uses the time of
diff --git a/builtin/am.c b/builtin/am.c
index dddf1b9..7e88d24 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -117,6 +117,7 @@ struct am_state {
 
 	/* various operating modes and command line options */
 	int interactive;
+	int no_verify;
 	int threeway;
 	int quiet;
 	int signoff; /* enum signoff_type */
@@ -472,10 +473,12 @@ static void am_destroy(const struct am_state *state)
  */
 static int run_applypatch_msg_hook(struct am_state *state)
 {
-	int ret;
+	int ret = 0;
 
 	assert(state->msg);
-	ret = run_hooks_l("applypatch-msg", am_path(state, "final-commit"), NULL);
+
+	if (!state->no_verify)
+		ret = run_hooks_l("applypatch-msg", am_path(state, "final-commit"), NULL);
 
 	if (!ret) {
 		FREE_AND_NULL(state->msg);
@@ -1650,7 +1653,7 @@ static void do_commit(const struct am_state *state)
 	const char *reflog_msg, *author, *committer = NULL;
 	struct strbuf sb = STRBUF_INIT;
 
-	if (run_hooks("pre-applypatch"))
+	if (!state->no_verify && run_hooks("pre-applypatch"))
 		exit(1);
 
 	if (write_cache_as_tree(&tree, 0, NULL))
@@ -2340,6 +2343,8 @@ int cmd_am(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_BOOL('i', "interactive", &state.interactive,
 			N_("run interactively")),
+		OPT_BOOL('n', "no-verify", &state.no_verify,
+			N_("bypass pre-applypatch and applypatch-msg hooks")),
 		OPT_HIDDEN_BOOL('b', "binary", &binary,
 			N_("historical option -- no-op")),
 		OPT_BOOL('3', "3way", &state.threeway,
diff --git a/csum-file.c b/csum-file.c
index 59ef339..cce13c0 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -45,7 +45,8 @@ void hashflush(struct hashfile *f)
 	unsigned offset = f->offset;
 
 	if (offset) {
-		the_hash_algo->update_fn(&f->ctx, f->buffer, offset);
+		if (!f->skip_hash)
+			the_hash_algo->update_fn(&f->ctx, f->buffer, offset);
 		flush(f, f->buffer, offset);
 		f->offset = 0;
 	}
@@ -64,7 +65,12 @@ int finalize_hashfile(struct hashfile *f, unsigned char *result,
 	int fd;
 
 	hashflush(f);
-	the_hash_algo->final_fn(f->buffer, &f->ctx);
+
+	if (f->skip_hash)
+		hashclr(f->buffer);
+	else
+		the_hash_algo->final_fn(f->buffer, &f->ctx);
+
 	if (result)
 		hashcpy(result, f->buffer);
 	if (flags & CSUM_HASH_IN_STREAM)
@@ -108,7 +114,8 @@ void hashwrite(struct hashfile *f, const void *buf, unsigned int count)
 			 * the hashfile's buffer. In this block,
 			 * f->offset is necessarily zero.
 			 */
-			the_hash_algo->update_fn(&f->ctx, buf, nr);
+			if (!f->skip_hash)
+				the_hash_algo->update_fn(&f->ctx, buf, nr);
 			flush(f, buf, nr);
 		} else {
 			/*
@@ -153,6 +160,7 @@ static struct hashfile *hashfd_internal(int fd, const char *name,
 	f->tp = tp;
 	f->name = name;
 	f->do_crc = 0;
+	f->skip_hash = 0;
 	the_hash_algo->init_fn(&f->ctx);
 
 	f->buffer_len = buffer_len;
diff --git a/csum-file.h b/csum-file.h
index 0d29f52..793a59d 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -20,6 +20,13 @@ struct hashfile {
 	size_t buffer_len;
 	unsigned char *buffer;
 	unsigned char *check_buffer;
+
+	/**
+	 * If non-zero, skip_hash indicates that we should
+	 * not actually compute the hash for this hashfile and
+	 * instead only use it as a buffered write.
+	 */
+	int skip_hash;
 };
 
 /* Checkpoint */
diff --git a/diff.c b/diff.c
index 9b14543..329eebf 100644
--- a/diff.c
+++ b/diff.c
@@ -4213,7 +4213,6 @@ static void prep_temp_blob(struct index_state *istate,
 }
 
 static struct diff_tempfile *prepare_temp_file(struct repository *r,
-					       const char *name,
 					       struct diff_filespec *one)
 {
 	struct diff_tempfile *temp = claim_diff_tempfile();
@@ -4231,18 +4230,18 @@ static struct diff_tempfile *prepare_temp_file(struct repository *r,
 
 	if (!S_ISGITLINK(one->mode) &&
 	    (!one->oid_valid ||
-	     reuse_worktree_file(r->index, name, &one->oid, 1))) {
+	     reuse_worktree_file(r->index, one->path, &one->oid, 1))) {
 		struct stat st;
-		if (lstat(name, &st) < 0) {
+		if (lstat(one->path, &st) < 0) {
 			if (errno == ENOENT)
 				goto not_a_valid_file;
-			die_errno("stat(%s)", name);
+			die_errno("stat(%s)", one->path);
 		}
 		if (S_ISLNK(st.st_mode)) {
 			struct strbuf sb = STRBUF_INIT;
-			if (strbuf_readlink(&sb, name, st.st_size) < 0)
-				die_errno("readlink(%s)", name);
-			prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
+			if (strbuf_readlink(&sb, one->path, st.st_size) < 0)
+				die_errno("readlink(%s)", one->path);
+			prep_temp_blob(r->index, one->path, temp, sb.buf, sb.len,
 				       (one->oid_valid ?
 					&one->oid : null_oid()),
 				       (one->oid_valid ?
@@ -4251,7 +4250,7 @@ static struct diff_tempfile *prepare_temp_file(struct repository *r,
 		}
 		else {
 			/* we can borrow from the file in the work tree */
-			temp->name = name;
+			temp->name = one->path;
 			if (!one->oid_valid)
 				oid_to_hex_r(temp->hex, null_oid());
 			else
@@ -4269,7 +4268,7 @@ static struct diff_tempfile *prepare_temp_file(struct repository *r,
 	else {
 		if (diff_populate_filespec(r, one, NULL))
 			die("cannot read data blob for %s", one->path);
-		prep_temp_blob(r->index, name, temp,
+		prep_temp_blob(r->index, one->path, temp,
 			       one->data, one->size,
 			       &one->oid, one->mode);
 	}
@@ -4278,10 +4277,9 @@ static struct diff_tempfile *prepare_temp_file(struct repository *r,
 
 static void add_external_diff_name(struct repository *r,
 				   struct strvec *argv,
-				   const char *name,
 				   struct diff_filespec *df)
 {
-	struct diff_tempfile *temp = prepare_temp_file(r, name, df);
+	struct diff_tempfile *temp = prepare_temp_file(r, df);
 	strvec_push(argv, temp->name);
 	strvec_push(argv, temp->hex);
 	strvec_push(argv, temp->mode);
@@ -4308,11 +4306,9 @@ static void run_external_diff(const char *pgm,
 	strvec_push(&cmd.args, name);
 
 	if (one && two) {
-		add_external_diff_name(o->repo, &cmd.args, name, one);
-		if (!other)
-			add_external_diff_name(o->repo, &cmd.args, name, two);
-		else {
-			add_external_diff_name(o->repo, &cmd.args, other, two);
+		add_external_diff_name(o->repo, &cmd.args, one);
+		add_external_diff_name(o->repo, &cmd.args, two);
+		if (other) {
 			strvec_push(&cmd.args, other);
 			strvec_push(&cmd.args, xfrm_msg);
 		}
@@ -7034,7 +7030,7 @@ static char *run_textconv(struct repository *r,
 	struct strbuf buf = STRBUF_INIT;
 	int err = 0;
 
-	temp = prepare_temp_file(r, spec->path, spec);
+	temp = prepare_temp_file(r, spec);
 	strvec_push(&child.args, pgm);
 	strvec_push(&child.args, temp->name);
 
diff --git a/dir.c b/dir.c
index fbdb24f..4e99f0c 100644
--- a/dir.c
+++ b/dir.c
@@ -732,6 +732,13 @@ static void add_pattern_to_hashsets(struct pattern_list *pl, struct path_pattern
 		goto clear_hashmaps;
 	}
 
+	if (!(given->flags & PATTERN_FLAG_MUSTBEDIR) &&
+	    strcmp(given->pattern, "/*")) {
+		/* Not a cone pattern. */
+		warning(_("unrecognized pattern: '%s'"), given->pattern);
+		goto clear_hashmaps;
+	}
+
 	prev = given->pattern;
 	cur = given->pattern + 1;
 	next = given->pattern + 2;
diff --git a/read-cache.c b/read-cache.c
index 1ff518b..cf87ad7 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1817,6 +1817,8 @@ static int verify_hdr(const struct cache_header *hdr, unsigned long size)
 	git_hash_ctx c;
 	unsigned char hash[GIT_MAX_RAWSZ];
 	int hdr_version;
+	unsigned char *start, *end;
+	struct object_id oid;
 
 	if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
 		return error(_("bad signature 0x%08x"), hdr->hdr_signature);
@@ -1827,10 +1829,16 @@ static int verify_hdr(const struct cache_header *hdr, unsigned long size)
 	if (!verify_index_checksum)
 		return 0;
 
+	end = (unsigned char *)hdr + size;
+	start = end - the_hash_algo->rawsz;
+	oidread(&oid, start);
+	if (oideq(&oid, null_oid()))
+		return 0;
+
 	the_hash_algo->init_fn(&c);
 	the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
 	the_hash_algo->final_fn(hash, &c);
-	if (!hasheq(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz))
+	if (!hasheq(hash, start))
 		return error(_("bad index file sha1 signature"));
 	return 0;
 }
@@ -2920,9 +2928,13 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 	int ieot_entries = 1;
 	struct index_entry_offset_table *ieot = NULL;
 	int nr, nr_threads;
+	struct repository *r = istate->repo ? istate->repo : the_repository;
 
 	f = hashfd(tempfile->fd, tempfile->filename.buf);
 
+	prepare_repo_settings(r);
+	f->skip_hash = r->settings.index_skip_hash;
+
 	for (i = removed = extended = 0; i < entries; i++) {
 		if (cache[i]->ce_flags & CE_REMOVE)
 			removed++;
diff --git a/repo-settings.c b/repo-settings.c
index 3021921..3dbd3f0 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -47,6 +47,7 @@ void prepare_repo_settings(struct repository *r)
 	}
 	if (manyfiles) {
 		r->settings.index_version = 4;
+		r->settings.index_skip_hash = 1;
 		r->settings.core_untracked_cache = UNTRACKED_CACHE_WRITE;
 	}
 
@@ -61,6 +62,7 @@ void prepare_repo_settings(struct repository *r)
 	repo_cfg_bool(r, "pack.usesparse", &r->settings.pack_use_sparse, 1);
 	repo_cfg_bool(r, "core.multipackindex", &r->settings.core_multi_pack_index, 1);
 	repo_cfg_bool(r, "index.sparse", &r->settings.sparse_index, 0);
+	repo_cfg_bool(r, "index.skiphash", &r->settings.index_skip_hash, r->settings.index_skip_hash);
 
 	/*
 	 * The GIT_TEST_MULTI_PACK_INDEX variable is special in that
diff --git a/repository.h b/repository.h
index 6c461c5..e8c67ff 100644
--- a/repository.h
+++ b/repository.h
@@ -42,6 +42,7 @@ struct repo_settings {
 	struct fsmonitor_settings *fsmonitor; /* lazily loaded */
 
 	int index_version;
+	int index_skip_hash;
 	enum untracked_cache_setting core_untracked_cache;
 
 	int pack_use_sparse;
diff --git a/scalar.c b/scalar.c
index 6c52243..b49bb8c 100644
--- a/scalar.c
+++ b/scalar.c
@@ -143,6 +143,7 @@ static int set_recommended_config(int reconfigure)
 		{ "credential.validate", "false", 1 }, /* GCM4W-only */
 		{ "gc.auto", "0", 1 },
 		{ "gui.GCWarning", "false", 1 },
+		{ "index.skipHash", "false", 1 },
 		{ "index.threads", "true", 1 },
 		{ "index.version", "4", 1 },
 		{ "merge.stat", "false", 1 },
diff --git a/t/helper/test-bundle-uri.c b/t/helper/test-bundle-uri.c
index 5df5bc3..b18e760 100644
--- a/t/helper/test-bundle-uri.c
+++ b/t/helper/test-bundle-uri.c
@@ -76,8 +76,6 @@ usage:
 
 static int cmd_ls_remote(int argc, const char **argv)
 {
-	const char *uploadpack = NULL;
-	struct string_list server_options = STRING_LIST_INIT_DUP;
 	const char *dest;
 	struct remote *remote;
 	struct transport *transport;
@@ -95,11 +93,6 @@ static int cmd_ls_remote(int argc, const char **argv)
 		die(_("remote '%s' has no configured URL"), dest);
 
 	transport = transport_get(remote, NULL);
-	if (uploadpack)
-		transport_set_option(transport, TRANS_OPT_UPLOADPACK, uploadpack);
-	if (server_options.nr)
-		transport->server_options = &server_options;
-
 	if (transport_get_remote_bundle_uri(transport) < 0) {
 		error(_("could not get the bundle-uri list"));
 		status = 1;
diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index b563d6c..627267b 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -238,7 +238,7 @@ test_expect_success 'cone mode: match patterns' '
 test_expect_success 'cone mode: warn on bad pattern' '
 	test_when_finished mv sparse-checkout repo/.git/info/ &&
 	cp repo/.git/info/sparse-checkout . &&
-	echo "!/deep/deeper/*" >>repo/.git/info/sparse-checkout &&
+	echo "!/deep/deeper/*/" >>repo/.git/info/sparse-checkout &&
 	git -C repo read-tree -mu HEAD 2>err &&
 	test_i18ngrep "unrecognized negative pattern" err
 '
@@ -667,6 +667,15 @@ test_expect_success 'pattern-checks: starting "*"' '
 	check_read_tree_errors repo "a deep" "disabling cone pattern matching"
 '
 
+test_expect_success 'pattern-checks: non directory pattern' '
+	cat >repo/.git/info/sparse-checkout <<-\EOF &&
+	/deep/deeper1/a
+	EOF
+	check_read_tree_errors repo deep "disabling cone pattern matching" &&
+	check_files repo/deep deeper1 &&
+	check_files repo/deep/deeper1 a
+'
+
 test_expect_success 'pattern-checks: contained glob characters' '
 	for c in "[a]" "\\" "?" "*"
 	do
diff --git a/t/t1509-root-work-tree.sh b/t/t1509-root-work-tree.sh
index 553a3f6..c799f5b 100755
--- a/t/t1509-root-work-tree.sh
+++ b/t/t1509-root-work-tree.sh
@@ -221,7 +221,8 @@ test_expect_success 'setup' '
 	rm -rf /.git &&
 	echo "Initialized empty Git repository in /.git/" > expected &&
 	git init > result &&
-	test_cmp expected result
+	test_cmp expected result &&
+	git config --global --add safe.directory /
 '
 
 test_vars 'auto gitdir, root' ".git" "/" ""
@@ -242,7 +243,7 @@ say "auto bare gitdir"
 # DESTROYYYYY!!!!!
 test_expect_success 'setup' '
 	rm -rf /refs /objects /info /hooks &&
-	rm -f /expected /ls.expected /me /result &&
+	rm -f /HEAD /expected /ls.expected /me /result &&
 	cd / &&
 	echo "Initialized empty Git repository in /" > expected &&
 	git init --bare > result &&
@@ -255,4 +256,9 @@ test_expect_success 'go to /foo' 'cd /foo'
 
 test_vars 'auto gitdir, root' "/" "" ""
 
+test_expect_success 'cleanup root' '
+	rm -rf /.git /refs /objects /info /hooks /branches /foo &&
+	rm -f /HEAD /config /description /expected /ls.expected /me /result
+'
+
 test_done
diff --git a/t/t1600-index.sh b/t/t1600-index.sh
index 010989f..0ebbae1 100755
--- a/t/t1600-index.sh
+++ b/t/t1600-index.sh
@@ -65,6 +65,36 @@ test_expect_success 'out of bounds index.version issues warning' '
 	)
 '
 
+test_expect_success 'index.skipHash config option' '
+	rm -f .git/index &&
+	git -c index.skipHash=true add a &&
+	test_trailing_hash .git/index >hash &&
+	echo $(test_oid zero) >expect &&
+	test_cmp expect hash &&
+	git fsck &&
+
+	rm -f .git/index &&
+	git -c feature.manyFiles=true add a &&
+	test_trailing_hash .git/index >hash &&
+	cmp expect hash &&
+
+	rm -f .git/index &&
+	git -c feature.manyFiles=true \
+	    -c index.skipHash=false add a &&
+	test_trailing_hash .git/index >hash &&
+	! cmp expect hash &&
+
+	test_commit start &&
+	git -c protocol.file.allow=always submodule add ./ sub &&
+	git config index.skipHash false &&
+	git -C sub config index.skipHash true &&
+	>sub/file &&
+	git -C sub add a &&
+	test_trailing_hash .git/modules/sub/index >hash &&
+	test_cmp expect hash &&
+	git -C sub fsck
+'
+
 test_index_version () {
 	INDEX_VERSION_CONFIG=$1 &&
 	FEATURE_MANY_FILES=$2 &&
diff --git a/t/t4045-diff-relative.sh b/t/t4045-diff-relative.sh
index 198dfc9..9b46c4c 100755
--- a/t/t4045-diff-relative.sh
+++ b/t/t4045-diff-relative.sh
@@ -164,6 +164,35 @@ check_diff_relative_option subdir file2 true --no-relative --relative
 check_diff_relative_option . file2 false --no-relative --relative=subdir
 check_diff_relative_option . file2 true --no-relative --relative=subdir
 
+test_expect_success 'external diff with --relative' '
+	test_when_finished "git reset --hard" &&
+	echo changed >file1 &&
+	echo changed >subdir/file2 &&
+
+	write_script mydiff <<-\EOF &&
+	# hacky pretend diff; the goal here is just to make sure we got
+	# passed sensible input that we _could_ diff, without relying on
+	# the specific output of a system diff tool.
+	echo "diff a/$1 b/$1" &&
+	echo "--- a/$1" &&
+	echo "+++ b/$1" &&
+	echo "@@ -1 +0,0 @@" &&
+	sed "s/^/-/" "$2" &&
+	sed "s/^/+/" "$5"
+	EOF
+
+	cat >expect <<-\EOF &&
+	diff a/file2 b/file2
+	--- a/file2
+	+++ b/file2
+	@@ -1 +0,0 @@
+	-other content
+	+changed
+	EOF
+	GIT_EXTERNAL_DIFF=./mydiff git diff --relative=subdir >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'setup diff --relative unmerged' '
 	test_commit zero file0 &&
 	test_commit base subdir/file0 &&
diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index 7646e85..78cf1c8 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -345,6 +345,21 @@ test_expect_success 'am with failing applypatch-msg hook' '
 	test_cmp_rev first HEAD
 '
 
+test_expect_success 'am with failing applypatch-msg hook (no verify)' '
+	rm -fr .git/rebase-apply &&
+	git reset --hard &&
+	git checkout first &&
+	test_hook applypatch-msg <<-\EOF &&
+	echo hook-message >"$1"
+	exit 1
+	EOF
+	git am --no-verify patch1 &&
+	test_path_is_missing .git/rebase-apply &&
+	git diff --exit-code second &&
+	git log -1 --format=format:%B >actual &&
+	test_cmp msg actual
+'
+
 test_expect_success 'am with pre-applypatch hook' '
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
@@ -374,6 +389,23 @@ test_expect_success 'am with failing pre-applypatch hook' '
 	test_cmp_rev first HEAD
 '
 
+test_expect_success 'am with failing pre-applypatch hook (no verify)' '
+	rm -fr .git/rebase-apply &&
+	git reset --hard &&
+	git checkout first &&
+	touch empty-file &&
+	test_hook pre-applypatch <<-\EOF &&
+	rm empty-file
+	exit 1
+	EOF
+	git am --no-verify patch1 &&
+	test_path_is_missing .git/rebase-apply &&
+	test_path_is_file empty-file &&
+	git diff --exit-code second &&
+	git log -1 --format=format:%B >actual &&
+	test_cmp msg actual
+'
+
 test_expect_success 'am with post-applypatch hook' '
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index f036c4d..1b8d434 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1450,72 +1450,6 @@ test_skip_or_die () {
 	error "$2"
 }
 
-# The following mingw_* functions obey POSIX shell syntax, but are actually
-# bash scripts, and are meant to be used only with bash on Windows.
-
-# A test_cmp function that treats LF and CRLF equal and avoids to fork
-# diff when possible.
-mingw_test_cmp () {
-	# Read text into shell variables and compare them. If the results
-	# are different, use regular diff to report the difference.
-	local test_cmp_a= test_cmp_b=
-
-	# When text came from stdin (one argument is '-') we must feed it
-	# to diff.
-	local stdin_for_diff=
-
-	# Since it is difficult to detect the difference between an
-	# empty input file and a failure to read the files, we go straight
-	# to diff if one of the inputs is empty.
-	if test -s "$1" && test -s "$2"
-	then
-		# regular case: both files non-empty
-		mingw_read_file_strip_cr_ test_cmp_a <"$1"
-		mingw_read_file_strip_cr_ test_cmp_b <"$2"
-	elif test -s "$1" && test "$2" = -
-	then
-		# read 2nd file from stdin
-		mingw_read_file_strip_cr_ test_cmp_a <"$1"
-		mingw_read_file_strip_cr_ test_cmp_b
-		stdin_for_diff='<<<"$test_cmp_b"'
-	elif test "$1" = - && test -s "$2"
-	then
-		# read 1st file from stdin
-		mingw_read_file_strip_cr_ test_cmp_a
-		mingw_read_file_strip_cr_ test_cmp_b <"$2"
-		stdin_for_diff='<<<"$test_cmp_a"'
-	fi
-	test -n "$test_cmp_a" &&
-	test -n "$test_cmp_b" &&
-	test "$test_cmp_a" = "$test_cmp_b" ||
-	eval "diff -u \"\$@\" $stdin_for_diff"
-}
-
-# $1 is the name of the shell variable to fill in
-mingw_read_file_strip_cr_ () {
-	# Read line-wise using LF as the line separator
-	# and use IFS to strip CR.
-	local line
-	while :
-	do
-		if IFS=$'\r' read -r -d $'\n' line
-		then
-			# good
-			line=$line$'\n'
-		else
-			# we get here at EOF, but also if the last line
-			# was not terminated by LF; in the latter case,
-			# some text was read
-			if test -z "$line"
-			then
-				# EOF, really
-				break
-			fi
-		fi
-		eval "$1=\$$1\$line"
-	done
-}
-
 # Like "env FOO=BAR some-program", but run inside a subshell, which means
 # it also works for shell functions (though those functions cannot impact
 # the environment outside of the test_env invocation).
@@ -1882,3 +1816,11 @@ test_cmp_config_output () {
 	sort config-actual >sorted-actual &&
 	test_cmp sorted-expect sorted-actual
 }
+
+# Given a filename, extract its trailing hash as a hex string
+test_trailing_hash () {
+	local file="$1" &&
+	tail -c $(test_oid rawsz) "$file" |
+		test-tool hexdump |
+		sed "s/ //g"
+}
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 6db377f..4fab1c1 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1721,7 +1721,7 @@ case $uname_s in
 	test_set_prereq SED_STRIPS_CR
 	test_set_prereq GREP_STRIPS_CR
 	test_set_prereq WINDOWS
-	GIT_TEST_CMP=mingw_test_cmp
+	GIT_TEST_CMP="GIT_DIR=/dev/null git diff --no-index --ignore-cr-at-eol --"
 	;;
 *CYGWIN*)
 	test_set_prereq POSIXPERM