fix crash in small window and branches

fixes #1470

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * fix key binding shown in bottom bar for `stash_open` ([#1454](https://github.com/extrawurst/gitui/issues/1454))
 * `--bugreport` does not require param ([#1466](https://github.com/extrawurst/gitui/issues/1466))
 * `edit`-file command shown on commits msg ([#1461](https://github.com/extrawurst/gitui/issues/1461))
+* crash on branches popup in small terminal ([#1470](https://github.com/extrawurst/gitui/issues/1470))
 
 ## [0.22.1] - 2022-11-22
 

src/ui/mod.rs

@@ -87,8 +87,18 @@ pub fn centered_rect(
 
 /// makes sure Rect `r` at least stays as big as min and not bigger than max
 pub fn rect_inside(min: Size, max: Size, r: Rect) -> Rect {
-	let new_width = r.width.clamp(min.width, max.width);
-	let new_height = r.height.clamp(min.height, max.height);
+	let new_width = if min.width > max.width {
+		max.width
+	} else {
+		r.width.clamp(min.width, max.width)
+	};
+
+	let new_height = if min.height > max.height {
+		max.width
+	} else {
+		r.height.clamp(min.height, max.height)
+	};
+
 	let diff_width = new_width.saturating_sub(r.width);
 	let diff_height = new_height.saturating_sub(r.height);
 
@@ -142,3 +152,40 @@ pub fn common_nav(
 		None
 	}
 }
+
+#[cfg(test)]
+mod test {
+	use super::{rect_inside, Size};
+	use pretty_assertions::assert_eq;
+	use tui::layout::Rect;
+
+	#[test]
+	fn test_small_rect_in_rect() {
+		let rect = rect_inside(
+			Size {
+				width: 2,
+				height: 2,
+			},
+			Size {
+				width: 1,
+				height: 1,
+			},
+			Rect {
+				x: 0,
+				y: 0,
+				width: 10,
+				height: 10,
+			},
+		);
+
+		assert_eq!(
+			rect,
+			Rect {
+				x: 0,
+				y: 0,
+				width: 1,
+				height: 1
+			}
+		);
+	}
+}