Truncate the query string if it's too long

Use hard-coded limit to keep it simple. An alternative is to dynamically
calculate the width of the visible area and use it as the limit, but it
can cause unwanted truncation of the query on screen resize/split.

src/constants.go

@@ -22,6 +22,7 @@ const (
 	initialDelay     = 20 * time.Millisecond
 	initialDelayTac  = 100 * time.Millisecond
 	spinnerDuration  = 200 * time.Millisecond
+	maxPatternLength = 100
 
 	// Matcher
 	numPartitionsMultiplier = 8

src/terminal.go

@@ -1337,6 +1337,11 @@ func (t *Terminal) Loop() {
 			if !doAction(action, mapkey) {
 				continue
 			}
+			// Truncate the query if it's too long
+			if len(t.input) > maxPatternLength {
+				t.input = t.input[:maxPatternLength]
+				t.cx = util.Constrain(t.cx, 0, maxPatternLength)
+			}
 			changed = string(previousInput) != string(t.input)
 		} else {
 			if mapkey == C.Rune {