my_strftime: Test for trivial case before anything else

If the passed in format is the empty string, the result is going to also
be the empty string.  There is no need to do any other work.

1 files changed, 11 insertions, 5 deletions

diff --git a/util.c b/util.c
index 66a19bcac9..6e5ecd44fc 100644
--- a/util.c
+++ b/util.c
@@ -4095,6 +4095,14 @@ and LC_TIME are not the same locale.
  */
     PERL_ARGS_ASSERT_MY_STRFTIME;
 
+    /* An empty format yields an empty result */
+    const int fmtlen = strlen(fmt);
+    if (fmtlen == 0) {
+        char *ret;
+        Newxz (ret, 1, char);
+        return ret;
+    }
+
     /* Set mytm to now */
     struct tm mytm;
     init_tm(&mytm);	/* XXX workaround - see init_tm() above */
@@ -4146,17 +4154,15 @@ and LC_TIME are not the same locale.
     ** indicate one of the following:
     ** 1. buffer overflowed,
     ** 2. illegal conversion specifier, or
-    ** 3. the format string specifies nothing to be returned (which isn't an
-    **    an error).  This could be because the format is an empty string
-    **    or it specifies %p which yields an empty string in some locales.
+    ** 3. the format string is %p which yields an empty string in some locales.
+    **    (which isn't an error).
     ** If there is a better way to make it portable, go ahead by
     ** all means.
     */
-    if (inRANGE(len, 1, buflen - 1) || (len == 0 && *fmt == '\0'))
+    if (inRANGE(len, 1, buflen - 1))
         return buf;
     else {
         /* Possibly buf overflowed - try again with a bigger buf */
-        const int fmtlen = strlen(fmt);
         int bufsize = fmtlen + buflen;
   
         Renew(buf, bufsize, char);