Don't read the wrong value in cursor_pos.

It seems like sometimes a slow terminal like lxterminal can take a
little while to respond with the cursor position, so the read can time
out. If it does, a later call to cursor_pos could read it in. To prevent
this, we can call read before even querying the position. If there are
any previous pending status responses, this should hopefully read them
in, and we can abort early without getting confused. If there is no
buffered data on stdin, then it's hopefully safe to write the status
query and read the response.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/term.rs b/src/term.rs
index 33d9d7c..d77a8f6 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -109,6 +109,12 @@ pub fn read_key(stdin: &mut BufReader<Stdin>) -> Result<Key, Box<dyn Error>> {
 // cursor_pos *WILL* fail if the user is typing on the keyboard. Be sure to handle
 // errors appropriately.
 pub fn cursor_pos(stdin: &mut BufReader<Stdin>) -> Result<(u16, u16), Box<dyn Error>> {
+    let buf = stdin.fill_buf()?;
+    if buf.len() > 0 {
+        // If there is any buffered input, the below call to fill_buf will just return the buffered
+        // data and not actually read the terminal response.
+        return Err(Box::from("interrupted"));
+    }
     write!(stdout(), "\x1b[6n")?;
     stdout().flush()?;
     let buf = stdin.fill_buf()?;