Fix segfault when restoring w_alt.cursor.

This fixes a crash when the window is made too small (zero height).
The crash can be reproduced by turning on altscreen and caption, and
resizing the terminal window to height = 1. After this, if the
termianl window height is increased, screen would crash when going
out of the alt screen.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/resize.c b/src/resize.c
index 0e491eb..3c2b90f 100644
--- a/src/resize.c
+++ b/src/resize.c
@@ -966,14 +966,16 @@ int wi, he, hi;
     p->w_y = he - 1;
   if (p->w_saved.x > wi)
     p->w_saved.x = wi;
-  if (p->w_saved.y < 0)
-    p->w_saved.y = 0;
   if (p->w_saved.y >= he)
     p->w_saved.y = he - 1;
+  if (p->w_saved.y < 0)
+    p->w_saved.y = 0;
   if (p->w_alt.cursor.x > wi)
     p->w_alt.cursor.x = wi;
   if (p->w_alt.cursor.y >= he)
     p->w_alt.cursor.y = he - 1;
+  if (p->w_alt.cursor.y < 0)
+    p->w_alt.cursor.y = 0;
 
   /* reset scrolling region */
   p->w_top = 0;