patch 8.0.0490: vertical split makes 'winfixwidth' window smaller
Problem: Splitting a 'winfixwidth' window vertically makes it one column
smaller. (Dominique Pelle)
Solution: Add one to the width for the separator.
diff --git a/src/window.c b/src/window.c
index 867f063..eed0ea9 100644
--- a/src/window.c
+++ b/src/window.c
@@ -870,9 +870,9 @@
/* We don't like to take lines for the new window from a
* 'winfixwidth' window. Take them from a window to the left or right
- * instead, if possible. */
+ * instead, if possible. Add one for the separator. */
if (oldwin->w_p_wfw)
- win_setwidth_win(oldwin->w_width + new_size, oldwin);
+ win_setwidth_win(oldwin->w_width + new_size + 1, oldwin);
/* Only make all windows the same width if one of them (except oldwin)
* is wider than one of the split windows. */