bin/59050: Discrepancy between ed behaviour and man page and POSIX

[carsten.reith%t-online.de@localhost]

>Number:         59050
>Category:       bin
>Synopsis:       Discrepancy between ed behaviour and man page and POSIX
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Feb 06 22:50:00 +0000 2025
>Originator:     Carsten Reith
>Release:        10.1-STABLE
>Organization:
>Environment:
NetBSD mogli.creith.de 10.1_STABLE NetBSD 10.1_STABLE (MOGLI) #0: Thu Feb  6 17:48:39 CET 2025  creith%mogli.creith.de@localhost:/home/creith/netbsd/obj/sys/arch/amd64/compile/MOGLI amd64
>Description:
According to the man page and POSIX, a missing trailing delimiter in a substitution should be equivalent to <delimter>p (f.ex. /p). This doesn't work with % (repeat last substitution.)


>How-To-Repeat:
mogli$ printf "a\nb\nc\n" > test
mogli$ ed test
6
1s/a/hello
hello
2s/b/%
%
,n
1       hello
2       %
3       c

>Fix:
After applying the following diff, ed works as expected.

Index: sub.c
===================================================================
RCS file: /cvsroot/src/bin/ed/sub.c,v
retrieving revision 1.7
diff -u -r1.7 sub.c
--- sub.c       23 Mar 2014 05:06:42 -0000      1.7
+++ sub.c       6 Feb 2025 22:18:46 -0000
@@ -84,7 +84,8 @@
        char c;
        char delimiter = *ibufp++;
 
-       if (*ibufp == '%' && *(ibufp + 1) == delimiter) {
+       if (*ibufp == '%' && 
+           (*(ibufp + 1) == delimiter || *(ibufp + 1) == '\n')) {
                ibufp++;
                if (!rhbuf) {
                        seterrmsg("no previous substitution");

Ed session after diff:

mogli$ printf "a\nb\nc\n" > test
mogli$ ed test
6
,n
1       a
2       b
3       c
1s/a/hello
hello
2s/b/%
hello
.n
2       hello
,n
1       hello
2       hello
3       c