patch 8.0.1526: no test using a screen dump yet

Problem:    No test using a screen dump yet.
Solution:   Add a test for C syntax highlighting.  Add helper functions.
diff --git a/src/terminal.c b/src/terminal.c
index 0f9aa86..73554a1 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -410,10 +410,13 @@
 
     if (!opt->jo_hidden)
     {
-	/* only one size was taken care of with :new, do the other one */
-	if (opt->jo_term_rows > 0 && (cmdmod.split & WSP_VERT))
+	/* Only one size was taken care of with :new, do the other one.  With
+	 * "curwin" both need to be done. */
+	if (opt->jo_term_rows > 0 && (opt->jo_curwin
+						 || (cmdmod.split & WSP_VERT)))
 	    win_setheight(opt->jo_term_rows);
-	if (opt->jo_term_cols > 0 && !(cmdmod.split & WSP_VERT))
+	if (opt->jo_term_cols > 0 && (opt->jo_curwin
+						|| !(cmdmod.split & WSP_VERT)))
 	    win_setwidth(opt->jo_term_cols);
     }