commit 72e3f6c7c05b4d5b56388508bb20a863aec279f5
from: Ivan Tham <pickfire@riseup.net>
via: Hiltjo Posthuma <hiltjo@codemadness.org>
date: Sun Apr 19 17:39:48 2020 UTC

Update XIM cursor position only if changed

Updating XIM cursor position is expensive, so only update it when cursor
position changed.

commit - 33a9a456644ceb235ea6ce61282f3bdce7a8b547
commit + 72e3f6c7c05b4d5b56388508bb20a863aec279f5
blob - 9e568c628471574456fa41f1260e6e70f943eda3
blob + 0ce6ac24591968723c7b70e5cb0af992df8e67b5
--- st.c
+++ st.c
@@ -2571,6 +2571,7 @@ void
 drawregion(int x1, int y1, int x2, int y2)
 {
 	int y;
+
 	for (y = y1; y < y2; y++) {
 		if (!term.dirty[y])
 			continue;
@@ -2583,7 +2584,7 @@ drawregion(int x1, int y1, int x2, int y2)
 void
 draw(void)
 {
-	int cx = term.c.x;
+	int cx = term.c.x, ocx = term.ocx, ocy = term.ocy;
 
 	if (!xstartdraw())
 		return;
@@ -2599,9 +2600,11 @@ draw(void)
 	drawregion(0, 0, term.col, term.row);
 	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
 			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
-	term.ocx = cx, term.ocy = term.c.y;
+	term.ocx = cx;
+	term.ocy = term.c.y;
 	xfinishdraw();
-	xximspot(term.ocx, term.ocy);
+	if (ocx != term.ocx || ocy != term.ocy)
+		xximspot(term.ocx, term.ocy);
 }
 
 void