Avoid a redundant check in mro.c

This code is never reached if oldstash is a hash without an HvENAME.

So instead of checking oldstash in the ?:, then hvename in the if(),
we can do one check.

If oldstash is no longer in the symbol table, then this code is never
reached, because of the if(!fetched_isarev) guard.

1 files changed, 10 insertions, 6 deletions

diff --git a/mro.c b/mro.c
index 4b90e6716b..ec0fb60291 100644
--- a/mro.c
+++ b/mro.c
@@ -984,13 +984,17 @@ S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes,
     if(!fetched_isarev) {
 	/* If oldstash is not null, then we can use its HvENAME to look up
 	   the isarev hash, since all its subclasses will be listed there.
+	   It will always have an HvENAME. It the HvENAME was removed
+	   above, then fetch_isarev will be true, and this code will not be
+	   reached.
 
-	   If oldstash is null or is no longer in the symbol table, then
-	   this is an empty spot with no stash in it, so subclasses could
-	   be listed in isarev hashes belonging to any of the names, so we
-	   have to check all of them. */
-	char *hvename = oldstash ? HvENAME(oldstash) : NULL;
-	if (hvename) {
+	   If oldstash is null, then this is an empty spot with no stash in
+	   it, so subclasses could be listed in isarev hashes belonging to
+	   any of the names, so we have to check all of them.
+	 */
+	if (oldstash) {
+	    /* Extra variable to avoid a compiler warning */
+	    char * const hvename = HvENAME(oldstash);
 	    fetched_isarev = TRUE;
 	    svp = hv_fetch(PL_isarev, hvename, HvENAMELEN_get(oldstash), 0);
 	    if (svp) isarev = MUTABLE_HV(*svp);