PATCH: fix :W and :w duplicating input

Reported in 50991 and introduced in 22525.
---
 Src/subst.c            | 2 +-
 Test/D04parameter.ztst | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Src/subst.c b/Src/subst.c
index f72a6baf27..1776d5e164 100644
--- a/Src/subst.c
+++ b/Src/subst.c
@@ -4737,7 +4737,6 @@ modify(char **str, char **ptr, int inbrace)
 		    *e = '\0';
 		    if (c != 'l' && c != 'u')
 			copy = dupstring(tt);
-		    *e = tc;
 		    switch (c) {
                     case 'a':
 			chabspath(&copy);
@@ -4804,6 +4803,7 @@ modify(char **str, char **ptr, int inbrace)
 			copy = xsymlink(copy, 1);
 			break;
 		    }
+		    *e = tc;
 		    tc = *tt;
 		    *tt = '\0';
 		    nl = al + strlen(t) + strlen(copy);
diff --git a/Test/D04parameter.ztst b/Test/D04parameter.ztst
index 21b1b9dcea..c09821c85e 100644
--- a/Test/D04parameter.ztst
+++ b/Test/D04parameter.ztst
@@ -1911,6 +1911,14 @@
 >
 >
 
+   wu='aa bb cc'
+   echo $wu:wu
+   W=FOOBAR
+   echo $W:W_B_l
+0:repeated upper/lowercase modifiers
+>AA BB CC
+>fooBar
+
 # This used to cause uncontrolled behaviour, but at best
 # you got the wrong output so the check is worth it.
    args() { print $#; }
-- 
2.38.1