test/kvs: Add KVS_NO_MERGE test in commitmerge

Add additional KVS_NO_MERGE test in kvs/commitmerge.  If KVS
commit-merge flag is true, and all commits set the KVS_NO_MERGE
flag, the behavior should be similar to when commit-merge=0.

t/kvs/commitmerge.c

@@ -68,14 +68,21 @@ static int threadcount = -1;
 static int changecount = 0;
 static char *prefix = NULL;
 static char *key = NULL;
+static bool nopt = false;
 
 static int watch_init = 0;
 static pthread_cond_t watch_init_cond = PTHREAD_COND_INITIALIZER;
 static pthread_mutex_t watch_init_lock = PTHREAD_MUTEX_INITIALIZER;
 
+#define OPTIONS "n"
+static const struct option longopts[] = {
+    {"nomerge", no_argument, 0, 'n'},
+    {0, 0, 0, 0},
+};
+
 static void usage (void)
 {
-    fprintf (stderr, "Usage: commitmerge threadcount prefix\n");
+    fprintf (stderr, "Usage: commitmerge [--nomerge] threadcount prefix\n");
     exit (1);
 }
 
@@ -193,8 +200,14 @@ void *committhread (void *arg)
     if (kvs_put_int (t->h, key, t->n) < 0)
         log_err_exit ("%s", key);
 
-    if (kvs_commit (t->h) < 0)
-        log_err_exit ("kvs_commit");
+    if (nopt) {
+        if (kvs_commit_flags (t->h, KVS_NO_MERGE) < 0)
+            log_err_exit ("kvs_commit");
+    }
+    else {
+        if (kvs_commit (t->h) < 0)
+            log_err_exit ("kvs_commit");
+    }
 
     flux_close (t->h);
     return NULL;
@@ -203,10 +216,20 @@ void *committhread (void *arg)
 int main (int argc, char *argv[])
 {
     thd_t *thd;
-    int i, rc;
+    int i, rc, ch;
 
     log_init (basename (argv[0]));
 
+    while ((ch = getopt_long (argc, argv, OPTIONS, longopts, NULL)) != -1) {
+        switch (ch) {
+        case 'n':
+            nopt = true;
+            break;
+        default:
+            usage ();
+        }
+    }
+
     if (argc - optind != 2)
         usage ();
 

t/t1000-kvs-basic.t

@@ -631,6 +631,18 @@ test_expect_success 'kvs: copy-tokvs and copy-fromkvs work' '
 	test_cmp random.data reread.data
 '
 
+# kvs merging tests
+
+# If commit-merge=1 and we set KVS_NO_MERGE on all commits, this test
+# should behave similarly to commit-merge=0 and OUTPUT should equal
+# THREADS.
+test_expect_success 'kvs: test that KVS_NO_MERGE works with kvs_commit()' '
+        THREADS=64 &&
+        OUTPUT=`${FLUX_BUILD_DIR}/t/kvs/commitmerge --nomerge ${THREADS} \
+                $(basename ${SHARNESS_TEST_FILE})`
+	test "$OUTPUT" = "${THREADS}"
+'
+
 # All tests below assume commit-merge=0
 
 # commit-merge option test