fixup! job-info: support job info CURRENT lookup flag

This is a minor optimization to avoid an extra json_dumps() call, doesn't
look that pretty, is ok?

src/modules/job-info/lookup.c

@@ -159,7 +159,7 @@ static int lookup_current (struct lookup_ctx *l,
                            flux_future_t *fall,
                            const char *key,
                            const char *value,
-                           char **current_value)
+                           json_t **current_object)
 {
     flux_future_t *f_eventlog;
     const char *s_eventlog;
@@ -168,7 +168,6 @@ static int lookup_current (struct lookup_ctx *l,
     size_t index;
     json_t *entry;
     const char *update_event_name = NULL;
-    char *value_object_str = NULL;
     int save_errno;
 
     if (streq (key, "R"))
@@ -208,19 +207,14 @@ static int lookup_current (struct lookup_ctx *l,
         }
     }
 
-    if (!(value_object_str = json_dumps (value_object, 0)))
-        goto error;
-
-    (*current_value) = value_object_str;
+    (*current_object) = value_object;
     json_decref (eventlog);
-    json_decref (value_object);
     return 0;
 
 error:
     save_errno = errno;
     json_decref (eventlog);
     json_decref (value_object);
-    free (value_object_str);
     errno = save_errno;
     return -1;
 }
@@ -289,9 +283,25 @@ static void info_lookup_continuation (flux_future_t *fall, void *arg)
 
         if ((l->flags & FLUX_JOB_LOOKUP_CURRENT)
             && streq (keystr, "R")) {
-            if (lookup_current (l, fall, keystr, s, &current_value) < 0)
+            json_t *current_object = NULL;
+            if (lookup_current (l, fall, keystr, s, &current_object) < 0)
                 goto error;
-            s = current_value;
+            /* tiny optimization, to skip unnecessary json_dumps() and
+             * fallthrough to code below
+             */
+            if (l->flags & FLUX_JOB_LOOKUP_JSON_DECODE) {
+                val = current_object;
+                goto store;
+            }
+            else {
+                if (!(current_value = json_dumps (current_object, 0))) {
+                    errno = ENOMEM;
+                    json_decref (current_object);
+                    goto error;
+                }
+                s = current_value;
+                json_decref (current_object);
+            }
         }
 
         /* check for JSON_DECODE flag last, as changes above could affect
@@ -309,6 +319,7 @@ static void info_lookup_continuation (flux_future_t *fall, void *arg)
                 goto enomem;
         }
 
+    store:
         if (json_object_set_new (o, keystr, val) < 0) {
             json_decref (val);
             goto enomem;