fix cursor bug + fix crash

src/core/file_buffer.odin

@@ -88,15 +88,17 @@ file_buffer_end :: proc(buffer: ^FileBuffer) -> Cursor {
 iterate_file_buffer :: proc(it: ^FileBufferIter) -> (character: u8, idx: PieceTableIndex, cond: bool) {
     character, idx, cond = iterate_piece_table_iter(&it.piter)
 
+    it.cursor.index = it.piter.index
+    it.hit_end = it.piter.hit_end
+
+    if cond && !it.hit_end {
         if character == '\n' {
             it.cursor.col = 0
             it.cursor.line += 1
         } else {
             it.cursor.col += 1
         }
-
-    it.cursor.index = it.piter.index
-    it.hit_end = it.piter.hit_end
+    }
 
     return
 }
@@ -108,7 +110,7 @@ iterate_file_buffer_reverse :: proc(it: ^FileBufferIter) -> (character: u8, idx:
     it.cursor.index = it.piter.index
     it.hit_end = it.piter.hit_end
 
-    if cond {
+    if cond && !it.hit_end {
         if it.cursor.col > 0 {
             it.cursor.col -= 1
         } else if it.cursor.line > 0 {

src/panels/panels.odin

@@ -301,12 +301,14 @@ make_grep_panel :: proc(state: ^core.State) -> core.Panel {
         free_grep_results(rs_results)
 
         panel_state.selected_result = 0
+        if len(panel_state.query_results) > 0 {
             core.update_glyph_buffer_from_bytes(
                 &panel_state.glyphs,
                 transmute([]u8)panel_state.query_results[panel_state.selected_result].file_context,
                 panel_state.query_results[panel_state.selected_result].line,
             )
         }
+    }
 
     core.register_key_action(&input_map.mode[.Normal], .ENTER, proc(state: ^core.State) {
         if current_panel, ok := util.get(&state.panels, state.current_panel.? or_else -1).?; ok {

src/tests/tests.odin

@@ -536,6 +536,28 @@ move_to_beginning_of_line_from_start :: proc(t: ^testing.T) {
     expect_cursor_index(t, buffer.cursor, 0, 0)
 }
 
+@(test)
+append_end_of_line :: proc(t: ^testing.T) {
+    e := new_test_editor()
+    setup_empty_buffer(&e)
+
+    buffer := &e.buffers[0]
+
+    run_text_insertion(&e, "hello")
+
+    run_input_multiple(&e, press_key(.A), 1)
+    run_input_multiple(&e, press_key(.ESCAPE), 1)
+
+    expect_line_col(t, buffer.cursor, 0, 5)
+    expect_cursor_index(t, buffer.cursor, 1, 0)
+
+    run_input_multiple(&e, press_key(.A), 1)
+    run_input_multiple(&e, press_key(.ESCAPE), 1)
+
+    expect_line_col(t, buffer.cursor, 0, 5)
+    expect_cursor_index(t, buffer.cursor, 1, 0)
+}
+
 @(test)
 insert_line_under_current :: proc(t: ^testing.T) {
     e := new_test_editor()