Fix for table panic

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## To be released
 
+### Fixes
+
+* Some combinations of `Table` widths and `Rect` width would cause a panic due to accessing area
+outside the buffer - (#470)
+
 ## v0.15.0 - 2021-05-02
 
 ### Features

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tui"
-version = "0.15.0"
+version = "0.15.1"
 authors = ["Florian Dehau <work@fdehau.com>"]
 description = """
 A library to build rich terminal user interfaces or dashboards

src/buffer.rs

@@ -353,8 +353,10 @@ impl Buffer {
     }
 
     pub fn set_style(&mut self, area: Rect, style: Style) {
+        // Ensure styling doesn't overflow buffer - https://github.com/fdehau/tui-rs/issues/470
+        let right = min(area.right(), self.area.width);
         for y in area.top()..area.bottom() {
-            for x in area.left()..area.right() {
+            for x in area.left()..right {
                 self.get_mut(x, y).set_style(style);
             }
         }

tests/widgets_table.rs

@@ -715,3 +715,66 @@ fn widgets_table_should_render_even_if_empty() {
 
     terminal.backend().assert_buffer(&expected);
 }
+
+/// Testing fix for https://github.com/fdehau/tui-rs/issues/470
+#[test]
+fn widgets_table_columns_dont_panic() {
+    let test_case = |state: &mut TableState, table: Table, width: u16| {
+        let backend = TestBackend::new(width, 8);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal
+            .draw(|f| {
+                let size = f.size();
+                f.render_stateful_widget(table, size, state);
+            })
+            .unwrap();
+    };
+
+    // based on https://github.com/fdehau/tui-rs/issues/470#issuecomment-852562848
+    let table1_width = 98;
+    let table1 = Table::new(vec![Row::new(vec!["r1", "r2", "r3", "r4"])])
+        .header(Row::new(vec!["h1", "h2", "h3", "h4"]))
+        .block(Block::default().borders(Borders::ALL))
+        .highlight_symbol(">> ")
+        .column_spacing(1)
+        .widths(&[
+            Constraint::Percentage(15),
+            Constraint::Percentage(15),
+            Constraint::Percentage(25),
+            Constraint::Percentage(45),
+        ]);
+
+    // based on https://github.com/fdehau/tui-rs/issues/470#issuecomment-831171722
+    let table2_width = 189;
+    let table2 = Table::new(vec![Row::new(vec![
+        "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+    ])])
+    .header(Row::new(vec![
+        "h1", "h2", "h3", "h4", "h5", "h6", "h7", "h8", "h9", "h10",
+    ]))
+    .block(Block::default().borders(Borders::TOP))
+    .highlight_style(Style::default().add_modifier(Modifier::REVERSED))
+    .highlight_symbol("=>")
+    .widths(&[
+        Constraint::Percentage(30),
+        Constraint::Percentage(10),
+        Constraint::Percentage(15),
+        Constraint::Percentage(10),
+        Constraint::Percentage(5),
+        Constraint::Percentage(5),
+        Constraint::Percentage(5),
+        Constraint::Percentage(5),
+        Constraint::Percentage(5),
+        Constraint::Percentage(10),
+    ]);
+
+    let mut state = TableState::default();
+    // no selection, no panic
+    test_case(&mut state, table1.clone(), table1_width);
+    test_case(&mut state, table2.clone(), table2_width);
+
+    // select first, which would cause a panic before fix
+    state.select(Some(0));
+    test_case(&mut state, table1.clone(), table1_width);
+    test_case(&mut state, table2.clone(), table2_width);
+}