t/helper/test-lazy-name-hash: fix compilation

stefanbeller · gitster · commit 74dea0e13cb5 · 2017-12-22T10:42:04.000-08:00
I was compiling origin/master today with DEVELOPER compiler flags
and was greeted by:

t/helper/test-lazy-init-name-hash.c: In function ‘cmd_main’:
t/helper/test-lazy-init-name-hash.c:172:5: error: ‘nr_threads_used’ may be used uninitilized in this function [-Werror=maybe-uninitialized]
     printf("avg [size %8d] [single %f] %c [multi %f %d]\n",
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         nr,
         ~~~
         (double)avg_single/1000000000,
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         (avg_single &lt; avg_multi ? '&lt;' : '&gt;'),
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         (double)avg_multi/1000000000,
         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
         nr_threads_used);
         ~~~~~~~~~~~~~~~~
t/helper/test-lazy-init-name-hash.c:115:6: note: ‘nr_threads_used’ was declared here
  int nr_threads_used;
      ^~~~~~~~~~~~~~~

I do not see how we can arrive at that line without having `nr_threads_used`
initialized, as we'd have `count &gt; 1`  (which asserts that we ran the
loop above at least once, such that it *should* be initialized).

Just clear the variable at the beginning of the function to squelch
the warning.

Signed-off-by: Stefan Beller &lt;sbeller@google.com&gt;
Acked-by: Jeff Hostetler &lt;jeffhost@microsoft.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/t/helper/test-lazy-init-name-hash.c b/t/helper/test-lazy-init-name-hash.c
@@ -112,7 +112,7 @@ static void analyze_run(void)
 {
 	uint64_t t1s, t1m, t2s, t2m;
 	int cache_nr_limit;
-	int nr_threads_used;
+	int nr_threads_used = 0;
 	int i;
 	int nr;
 

Original file line number	Diff line number	Diff line change
`@@ -112,7 +112,7 @@ static void analyze_run(void)`
`112`	`112`	`{`
`113`	`113`	`uint64_t t1s, t1m, t2s, t2m;`
`114`	`114`	`int cache_nr_limit;`
`115`		`- int nr_threads_used;`
	`115`	`+ int nr_threads_used = 0;`
`116`	`116`	`int i;`
`117`	`117`	`int nr;`
`118`	`118`