%#b in particular and %B in general were kaputt.

p4raw-id: //depot/cfgperl@4111

1 files changed, 5 insertions, 2 deletions

diff --git a/sv.c b/sv.c
index 956f3b961a..f6a793c40a 100644
--- a/sv.c
+++ b/sv.c
@@ -4959,6 +4959,7 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 	    base = 10;
 	    goto uns_integer;
 
+	case 'B':
 	case 'b':
 	    base = 2;
 	    goto uns_integer;
@@ -5033,8 +5034,10 @@ Perl_sv_vcatpvfn(pTHX_ SV *sv, const char *pat, STRLEN patlen, va_list *args, SV
 		    dig = uv & 1;
 		    *--eptr = '0' + dig;
 		} while (uv >>= 1);
-		if (alt && *eptr != '0')
-		    *--eptr = '0';
+		if (alt) {
+		    esignbuf[esignlen++] = '0';
+		    esignbuf[esignlen++] = c;  /* 'b' or 'B' */
+		}
 		break;
 	    default:		/* it had better be ten or less */
 		do {