preload-index: fix memleak

Fix a memory leak occuring in case of pathspec copy in preload_index.

Direct leak of 8 byte(s) in 8 object(s) allocated from:
    #0 0x7f0a353ead47 in __interceptor_malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/11.3.0/libasan.so.6+0xb5d47)
    helmo#1 0x55750995e840 in do_xmalloc /home/anthony/src/c/git/wrapper.c:51
    helmo#2 0x55750995e840 in xmalloc /home/anthony/src/c/git/wrapper.c:72
    helmo#3 0x55750970f824 in copy_pathspec /home/anthony/src/c/git/pathspec.c:684
    #4 0x557509717278 in preload_index /home/anthony/src/c/git/preload-index.c:135
    #5 0x55750975f21e in refresh_index /home/anthony/src/c/git/read-cache.c:1633
    git#6 0x55750915b926 in cmd_status builtin/commit.c:1547
    #7 0x5575090e1680 in run_builtin /home/anthony/src/c/git/git.c:466
    git#8 0x5575090e1680 in handle_builtin /home/anthony/src/c/git/git.c:720
    git#9 0x5575090e284a in run_argv /home/anthony/src/c/git/git.c:787
    git#10 0x5575090e284a in cmd_main /home/anthony/src/c/git/git.c:920
    git#11 0x5575090dbf82 in main /home/anthony/src/c/git/common-main.c:56
    git#12 0x7f0a348230ab  (/lib64/libc.so.6+0x290ab)

Signed-off-by: Anthony Delannoy <anthony.2lannoy@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: spnngl

preload-index.c

@@ -151,6 +151,12 @@ void preload_index(struct index_state *index,
 	}
 	stop_progress(&pd.progress);
 
+	if (pathspec) {
+		/* earlier we made deep copies for each thread to work with */
+		for (i = 0; i < threads; i++)
+			clear_pathspec(&data[i].pathspec);
+	}
+
 	trace_performance_leave("preload index");
 
 	trace2_data_intmax("index", NULL, "preload/sum_lstat", t2_sum_lstat);