Fix newline + scroll region bug (#747)

When a scroll region is active with the cursor below the bottom of the
region, newlines should not cause the region to scroll.

A ref test was added for this situation to prevent regressions.

Thanks @hiciu for reporting and @nicm for the test case.

Resolves #745.

src/term/mod.rs

@@ -1405,7 +1405,7 @@ impl ansi::Handler for Term {
     #[inline]
     fn linefeed(&mut self) {
         trace!("linefeed");
-        if (self.cursor.point.line + 1) >= self.scroll_region.end {
+        if (self.cursor.point.line + 1) == self.scroll_region.end {
             self.scroll_up(Line(1));
         } else {
             self.cursor.point.line += 1;

tests/ref/newline_with_cursor_beyond_scroll_region/alacritty.recording

@@ -0,0 +1,4 @@
+%                                                                                  
 
]2;jwilm@jwilm-desk: ~/code/alacritty]1;..ode/alacritty
jwilm@jwilm-desk ➜  ~/code/alacritty  [?1h=[?2004h
+bck-i-search: _clear; cat ~/Downloads/xtest.txt; sleep 100c_caa_att_clearcat ~/Downloads/xtest.txtsleep
[?1l>[?2004l
]2;clear; cat ~/Downloads/xtest.txt; sleep 100]1;clear;
+ 58         getprogname());                                                      59     exit                                                                    9 9
+ 59     !!!!

tests/ref/newline_with_cursor_beyond_scroll_region/size.json

@@ -0,0 +1 @@
+{"width":587.0,"height":360.0,"cell_width":7.0,"cell_height":16.0,"padding_x":3.0,"padding_y":3.0}