sh: Fix LINENO and prompt after $'\0 and newline.

bin/sh/parser.c

@@ -1279,6 +1279,13 @@ readcstyleesc(char *out)
 				c = pgetc();
 			if (c == PEOF)
 				synerror("Unterminated quoted string");
+			if (c == '\n') {
+				plinno++;
+				if (doprompt)
+					setprompt(2);
+				else
+					setprompt(0);
+			}
 		}
 		pungetc();
 		return out;

bin/sh/tests/builtins/Makefile

@@ -100,6 +100,7 @@ FILES+=		jobid2.0
 FILES+=		kill1.0 kill2.0
 FILES+=		lineno.0 lineno.0.stdout
 FILES+=		lineno2.0
+FILES+=		lineno3.0 lineno3.0.stdout
 FILES+=		local1.0
 FILES+=		local2.0
 FILES+=		local3.0

bin/sh/tests/builtins/lineno3.0

@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+echo before: $LINENO
+dummy=$'a\0
+'
+echo after: $LINENO

bin/sh/tests/builtins/lineno3.0.stdout

@@ -0,0 +1,2 @@
+before: 3
+after: 6