Fix !^:h and !^:t failing when no / found

Restore the behavior where both !^:h and !^:t return the whole string
when there is no / in !^ (or other similar history reference).

Related commits:
- ccd1e6d
- 05d3d6b

Author: suominen

Fixes

@@ -1,3 +1,4 @@
+ 36. Fix !^:h and !^:t failing when no / found (Kimmo Suominen)
  35. Add cross-build support for gethost (josefs10)
  34. Add support for $?< (Matheus Garcia)
  33. V6.24.12 - 2024-04-05

sh.lex.c

@@ -1069,7 +1069,7 @@ domod(Char *cp, Char type)
     case 't':
 	wp = Strrchr(cp, '/');
 	if (wp == NULL)
-	    return NULL;
+	    return Strsave(cp);
 	if (type == 't')
 	    xp = Strsave(wp + 1);
 	else

tests/lexical.at

@@ -455,6 +455,10 @@ AT_DATA([modifiers.csh],
 [[echo foo bar baz quux /usr/src/sys/sys/malloc.c
 ^baz^bash
 ^bar^kPa^:p
+echo !1:1:h
+echo !1:1:t
+echo !1:1:r
+echo !1:1:e
 echo !1:$:h
 echo !1:$:t
 echo !1:$:r
@@ -480,6 +484,10 @@ echo ${#var}
 AT_CHECK([tcsh -f -q -i < modifiers.csh], ,
 [[> foo bar baz quux /usr/src/sys/sys/malloc.c
 foo bar bash quux /usr/src/sys/sys/malloc.c
+foo
+foo
+foo
+
 /usr/src/sys/sys
 malloc.c
 /usr/src/sys/sys/malloc
@@ -501,6 +509,10 @@ f[oo][oo] bar baz quux /usr/src/sys/sys/mall[oo]c.c
 ]],
 [[echo foo bar bash quux /usr/src/sys/sys/malloc.c
 echo foo kPa bash quux /usr/src/sys/sys/malloc.c
+echo foo
+echo foo
+echo foo
+echo
 echo /usr/src/sys/sys
 echo malloc.c
 echo /usr/src/sys/sys/malloc