preserve all text attributes on cleared cells

some terminals require it (alacritty wants to render underline and
inverse state of cleared cells, for instance, so we have to be sure that
the diff algorithm will properly reset the cursor attributes before
clearing cells)

1 files changed, 44 insertions, 0 deletions

diff --git a/tests/attr.rs b/tests/attr.rs
index bd5aac9..a784388 100644
--- a/tests/attr.rs
+++ b/tests/attr.rs
@@ -171,6 +171,30 @@ fn colors() {
         parser.screen().cell(0, 1).unwrap().bgcolor(),
         vt100::Color::Idx(15)
     );
+
+    // make sure bgcolor is properly preserved on cleared cells
+    parser.process(b"\x1bcfoo");
+
+    assert_eq!(
+        parser.screen().cell(0, 1).unwrap().bgcolor(),
+        vt100::Color::Default
+    );
+    parser.process(b"\x1b[1;2H\x1b[41mo\x1b[m");
+    assert_eq!(
+        parser.screen().cell(0, 1).unwrap().bgcolor(),
+        vt100::Color::Idx(1)
+    );
+
+    assert_eq!(
+        parser.screen().cell(0, 0).unwrap().bgcolor(),
+        vt100::Color::Default
+    );
+    parser.process(b"\x1b[1;1H\x1b[41m\x1b[X\x1b[m");
+    assert_eq!(
+        parser.screen().cell(0, 0).unwrap().bgcolor(),
+        vt100::Color::Idx(1)
+    );
+    assert!(!parser.screen().cell(0, 0).unwrap().has_contents());
 }
 
 #[test]
@@ -222,4 +246,24 @@ fn attrs() {
     assert!(parser.screen().cell(0, 3).unwrap().italic());
     assert!(parser.screen().cell(0, 3).unwrap().underline());
     assert!(parser.screen().cell(0, 3).unwrap().inverse());
+
+    // alacritty renders underline and inverse status for empty cells, so make
+    // sure we reflect that here (so that we generate diffs correctly and
+    // such). unclear who is right here - other terminals don't do this, but
+    // terminals do generally render bgcolor for empty cells, which feels
+    // similar.
+    parser.process(b"\x1bcfoo");
+
+    assert!(!parser.screen().cell(0, 1).unwrap().underline());
+    assert!(!parser.screen().cell(0, 1).unwrap().inverse());
+    parser.process(b"\x1b[1;2H\x1b[4;7mo\x1b[m");
+    assert!(parser.screen().cell(0, 1).unwrap().underline());
+    assert!(parser.screen().cell(0, 1).unwrap().inverse());
+
+    assert!(!parser.screen().cell(0, 0).unwrap().underline());
+    assert!(!parser.screen().cell(0, 0).unwrap().inverse());
+    parser.process(b"\x1b[1;1H\x1b[4;7m\x1b[X\x1b[m");
+    assert!(parser.screen().cell(0, 0).unwrap().underline());
+    assert!(parser.screen().cell(0, 0).unwrap().inverse());
+    assert!(!parser.screen().cell(0, 0).unwrap().has_contents());
 }