utf8_to_uv_msgs: Move code to ensure initialization

There was a path through this function in which the caller's parameter
it asked to be set, &msgs, did not get set.  And doing it at the
beginning means not needing a second place.

Similarly for &errors.  There is no path where it didn't get set, but it
is cleaner to do it in at the same time as doing msgs.

Author: khwilliamson

utf8.c

@@ -1382,18 +1382,20 @@ Perl__utf8n_to_uvchr_msgs_helper(const U8 *s,
      * syllables that the dfa doesn't properly handle.  Quickly dispose of the
      * final case. */
 
+    /* Assume will be successful; override later if necessary */
+    if (errors) {
+        *errors = 0;
+    }
+    if (msgs) {
+        *msgs = NULL;
+    }
+
     /* Each of the affected Hanguls starts with \xED */
 
     if (is_HANGUL_ED_utf8_safe(s0, send)) { /* Always false on EBCDIC */
         if (retlen) {
             *retlen = 3;
         }
-        if (errors) {
-            *errors = 0;
-        }
-        if (msgs) {
-            *msgs = NULL;
-        }
 
         return ((0xED & UTF_START_MASK(3)) << (2 * UTF_ACCUMULATION_SHIFT))
              | ((s0[1] & UTF_CONTINUATION_MASK) << UTF_ACCUMULATION_SHIFT)
@@ -1669,11 +1671,6 @@ Perl__utf8n_to_uvchr_msgs_helper(const U8 *s,
         bool disallowed = FALSE;
         const U32 orig_problems = possible_problems;
 
-        if (msgs) {
-            *msgs = NULL;
-        }
-
-
         /* Returns 0 if no message needs to be generated for this problem even
          * if everything else says to.  Otherwise returns the warning category
          * to use for the message.