Merge branch 'jh/memihash-opt'

Hotfix for a topic that is already in 'master'.

* jh/memihash-opt:
  p0004: make perf test executable
  t3008: skip lazy-init test on a single-core box
  test-online-cpus: helper to return cpu count
  name-hash: fix buffer overrun

6 files changed, 40 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index c6dbeccf5e..eb1a1a7cff 100644
--- a/Makefile
+++ b/Makefile
@@ -626,6 +626,7 @@ TEST_PROGRAMS_NEED_X += test-line-buffer
 TEST_PROGRAMS_NEED_X += test-match-trees
 TEST_PROGRAMS_NEED_X += test-mergesort
 TEST_PROGRAMS_NEED_X += test-mktemp
+TEST_PROGRAMS_NEED_X += test-online-cpus
 TEST_PROGRAMS_NEED_X += test-parse-options
 TEST_PROGRAMS_NEED_X += test-path-utils
 TEST_PROGRAMS_NEED_X += test-prio-queue
diff --git a/name-hash.c b/name-hash.c
index cac313c78d..39309efb7f 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -342,7 +342,9 @@ static int handle_range_dir(
 	 * Scan forward in the index array for index entries having the same
 	 * path prefix (that are also in this directory).
 	 */
-	if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0)
+	if (k_start + 1 >= k_end)
+		k = k_end;
+	else if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0)
 		k = k_start + 1;
 	else if (strncmp(istate->cache[k_end - 1]->name, prefix->buf, prefix->len) == 0)
 		k = k_end;
diff --git a/t/helper/.gitignore b/t/helper/.gitignore
index d1fa751cf9..acd5db180f 100644
--- a/t/helper/.gitignore
+++ b/t/helper/.gitignore
@@ -16,6 +16,7 @@
 /test-match-trees
 /test-mergesort
 /test-mktemp
+/test-online-cpus
 /test-parse-options
 /test-path-utils
 /test-prio-queue
diff --git a/t/helper/test-online-cpus.c b/t/helper/test-online-cpus.c
new file mode 100644
index 0000000000..06c09c6b88
--- /dev/null
+++ b/t/helper/test-online-cpus.c
@@ -0,0 +1,8 @@
+#include "git-compat-util.h"
+#include "thread-utils.h"
+
+int cmd_main(int argc, const char **argv)
+{
+	printf("%d\n", online_cpus());
+	return 0;
+}
diff --git a/t/perf/p0004-lazy-init-name-hash.sh b/t/perf/p0004-lazy-init-name-hash.sh
index 5afa8c8df3..5afa8c8df3 100644..100755
--- a/t/perf/p0004-lazy-init-name-hash.sh
+++ b/t/perf/p0004-lazy-init-name-hash.sh
diff --git a/t/t3008-ls-files-lazy-init-name-hash.sh b/t/t3008-ls-files-lazy-init-name-hash.sh
new file mode 100755
index 0000000000..bdf5198b7e
--- /dev/null
+++ b/t/t3008-ls-files-lazy-init-name-hash.sh
@@ -0,0 +1,27 @@
+#!/bin/sh
+
+test_description='Test the lazy init name hash with various folder structures'
+
+. ./test-lib.sh
+
+if test 1 -eq $($GIT_BUILD_DIR/t/helper/test-online-cpus)
+then
+	skip_all='skipping lazy-init tests, single cpu'
+	test_done
+fi
+
+LAZY_THREAD_COST=2000
+
+test_expect_success 'no buffer overflow in lazy_init_name_hash' '
+	(
+	    test_seq $LAZY_THREAD_COST | sed "s/^/a_/"
+	    echo b/b/b
+	    test_seq $LAZY_THREAD_COST | sed "s/^/c_/"
+	    test_seq 50 | sed "s/^/d_/" | tr "\n" "/"; echo d
+	) |
+	sed "s/^/100644 $EMPTY_BLOB	/" |
+	git update-index --index-info &&
+	test-lazy-init-name-hash -m
+'
+
+test_done