diff --git a/bin/sh/parser.c b/bin/sh/parser.c
index f883dff2f2f7..075c04d6e488 100644
--- a/bin/sh/parser.c
+++ b/bin/sh/parser.c
@@ -1447,6 +1447,7 @@ parsesub: {
 	int bracketed_name = 0; /* used to handle ${[0-9]*} variables */
 	int linno;
 	int length;
+	int c1;
 
 	c = pgetc();
 	if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) &&
@@ -1473,15 +1474,9 @@ parsesub: {
 		if (c == '{') {
 			bracketed_name = 1;
 			c = pgetc();
-			if (c == '#') {
-				if ((c = pgetc()) == '}')
-					c = '#';
-				else
-					subtype = VSLENGTH;
-			}
-			else
-				subtype = 0;
+			subtype = 0;
 		}
+varname:
 		if (!is_eof(c) && is_name(c)) {
 			length = 0;
 			do {
@@ -1511,19 +1506,35 @@ parsesub: {
 				STPUTC(c, out);
 				c = pgetc();
 			}
-		} else {
-			if (! is_special(c)) {
-				subtype = VSERROR;
-				if (c == '}')
-					pungetc();
-				else if (c == '\n' || c == PEOF)
-					synerror("Unexpected end of line in substitution");
-				else
-					USTPUTC(c, out);
-			} else {
-				USTPUTC(c, out);
+		} else if (is_special(c)) {
+			c1 = c;
+			c = pgetc();
+			if (subtype == 0 && c1 == '#') {
+				subtype = VSLENGTH;
+				if (strchr(types, c) == NULL && c != ':' &&
+				    c != '#' && c != '%')
+					goto varname;
+				c1 = c;
 				c = pgetc();
+				if (c1 != '}' && c == '}') {
+					pungetc();
+					c = c1;
+					goto varname;
+				}
+				pungetc();
+				c = c1;
+				c1 = '#';
+				subtype = 0;
 			}
+			USTPUTC(c1, out);
+		} else {
+			subtype = VSERROR;
+			if (c == '}')
+				pungetc();
+			else if (c == '\n' || c == PEOF)
+				synerror("Unexpected end of line in substitution");
+			else
+				USTPUTC(c, out);
 		}
 		if (subtype == 0) {
 			switch (c) {
diff --git a/tools/regression/bin/sh/expansion/plus-minus8.0 b/tools/regression/bin/sh/expansion/plus-minus8.0
new file mode 100644
index 000000000000..beba009b0660
--- /dev/null
+++ b/tools/regression/bin/sh/expansion/plus-minus8.0
@@ -0,0 +1,5 @@
+# $FreeBSD$
+
+set -- 1 2 3 4 5 6 7 8 9 10 11 12 13
+[ "${#+hi}" = hi ] || echo '${#+hi} wrong'
+[ "${#-hi}" = 13 ] || echo '${#-hi} wrong'
diff --git a/tools/regression/bin/sh/expansion/trim7.0 b/tools/regression/bin/sh/expansion/trim7.0
new file mode 100644
index 000000000000..352bdea920bf
--- /dev/null
+++ b/tools/regression/bin/sh/expansion/trim7.0
@@ -0,0 +1,16 @@
+# $FreeBSD$
+
+set -- 1 2 3 4 5 6 7 8 9 10 11 12 13
+[ "${##1}" = 3 ] || echo '${##1} wrong'
+[ "${###1}" = 3 ] || echo '${###1} wrong'
+[ "${###}" = 13 ] || echo '${###} wrong'
+[ "${#%3}" = 1 ] || echo '${#%3} wrong'
+[ "${#%%3}" = 1 ] || echo '${#%%3} wrong'
+[ "${#%%}" = 13 ] || echo '${#%%} wrong'
+set --
+[ "${##0}" = "" ] || echo '${##0} wrong'
+[ "${###0}" = "" ] || echo '${###0} wrong'
+[ "${###}" = 0 ] || echo '${###} wrong'
+[ "${#%0}" = "" ] || echo '${#%0} wrong'
+[ "${#%%0}" = "" ] || echo '${#%%0} wrong'
+[ "${#%%}" = 0 ] || echo '${#%%} wrong'