st: guard tsetdirt() against zero-sized terminal

tsetdirt() assumes term.row > 0. During early init or
resize paths this may not hold, leading to out-of-bounds
access. Bail out early if there are no rows.

diff --git a/st.c b/st.c
index e55e7b33a16e35aa48f890a26ea11fbca4c9405d..6f40e35bc8585cda6584a26d37a44014cc56627c 100644 (file)
--- a/st.c
+++ b/st.c
@@ -965,6 +965,9 @@ tsetdirt(int top, int bot)
 {
        int i;
 
+       if (term.row <= 0)
+               return;
+
        LIMIT(top, 0, term.row-1);
        LIMIT(bot, 0, term.row-1);