ash: perform tilde expansion in all parameter expansion words

Previously tilde expansion was not carried out for =?#% expansion words.

Test case:
   a=~root:~root
   echo ${a#~root}
Old result:
   /root:/root
New result:
   :/root

Based on commit dd721f71 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu

function                                             old     new   delta
subevalvar                                          1152    1153      +1

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index a81922a..4c43f1f 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6361,8 +6361,8 @@
 	//		p, varname, strloc, subtype, startloc, varflags, quotes);
 
 	herefd = -1;
-	argstr(p, (subtype != VSASSIGN && subtype != VSQUESTION) ? EXP_CASE : 0,
-			var_str_list);
+	argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ?
+			EXP_CASE : 0), var_str_list);
 	STPUTC('\0', expdest);
 	herefd = saveherefd;
 	argbackq = saveargbackq;
diff --git a/shell/ash_test/ash-vars/var-expand-tilde-in-parameter-expansion.right b/shell/ash_test/ash-vars/var-expand-tilde-in-parameter-expansion.right
new file mode 100644
index 0000000..2357750
--- /dev/null
+++ b/shell/ash_test/ash-vars/var-expand-tilde-in-parameter-expansion.right
@@ -0,0 +1 @@
+:/root
diff --git a/shell/ash_test/ash-vars/var-expand-tilde-in-parameter-expansion.tests b/shell/ash_test/ash-vars/var-expand-tilde-in-parameter-expansion.tests
new file mode 100755
index 0000000..6605315
--- /dev/null
+++ b/shell/ash_test/ash-vars/var-expand-tilde-in-parameter-expansion.tests
@@ -0,0 +1,2 @@
+a=~root:~root
+echo ${a#~root}