Perl_sv_vcatpvfn_flags: simplify concat of f/p str

Since floating-point formats do their own formatting and padding, skip the
block of code at the end of the main loop which handles appending eptr to
sv, and do our own stripped-down version.

diff --git a/sv.c b/sv.c
index 1662eb8..2e5b9fc 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -12967,10 +12967,45 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
 
        float_converted:
            eptr = PL_efloatbuf;
-            assert((IV)elen > 0); /* here zero elen is bad */
 
+            /* Since floating-point formats do their own formatting and
+             * padding, we skip the main block of code at the end of this
+             * loop which handles appending eptr to sv, and do our own
+             * stripped-down version */
+
+            assert(!zeros);
+            assert(!esignlen);
+            assert(!vectorize);
+            assert(elen);
+            assert(elen >= width);
+
+            /* floating-point formats only get is_utf8 if the radix point
+             * is utf8. All other characters in the string are < 128
+             * and so can be safely appended to both a non-utf8 and utf8
+             * string as-is.
+             */
+            if (is_utf8 && !has_utf8) {
+                sv_utf8_upgrade(sv);
+                has_utf8 = TRUE;
+            }
 
-           break;
+            {
+                /* unrolled Perl_sv_catpvn */
+                STRLEN need = elen + SvCUR(sv) + 1;
+                char *end;
+                /* can't wrap as both elen and SvCUR() are allocated in
+                 * memory and together can't consume all the address space
+                 */
+                assert(need > elen);
+                SvGROW(sv, need);
+                end = SvEND(sv);
+                Copy(eptr, end, elen, char);
+                end += elen;
+                *end = '\0';
+                SvCUR_set(sv, need - 1);
+            }
+
+            goto donevalidconversion;
         }
 
            /* SPECIAL */