--- a/layout/base/tests/marionette/test_accessiblecaret_cursor_mode.py
+++ b/layout/base/tests/marionette/test_accessiblecaret_cursor_mode.py
@@ -17,17 +17,19 @@ class AccessibleCaretCursorModeTestCase(
     '''Test cases for AccessibleCaret under cursor mode.
 
     We call the blinking cursor (nsCaret) as cursor, and call AccessibleCaret as
     caret for short.
 
     '''
     # Element IDs.
     _input_id = 'input'
+    _input_padding_id = 'input-padding'
     _textarea_id = 'textarea'
+    _textarea_one_line_id = 'textarea-one-line'
     _contenteditable_id = 'contenteditable'
 
     # Test html files.
     _cursor_html = 'test_carets_cursor.html'
 
     def setUp(self):
         # Code to execute before every test is running.
         super(AccessibleCaretCursorModeTestCase, self).setUp()
@@ -180,35 +182,63 @@ class AccessibleCaretCursorModeTestCase(
         dest_x, dest_y = 0, 0
         self.actions.flick(el, src_x, src_y, dest_x, dest_y).perform()
 
         # The content should be inserted at the end of the <input>.
         el.send_keys(content_to_add)
 
         self.assertEqual(target_content, sel.content)
 
-    def test_caret_not_jump_when_dragging_to_editable_content_boundary(self):
+    @parameterized(_input_id, el_id=_input_id)
+    @parameterized(_input_padding_id, el_id=_input_padding_id)
+    @parameterized(_textarea_one_line_id, el_id=_textarea_one_line_id)
+    @parameterized(_contenteditable_id, el_id=_contenteditable_id)
+    def test_caret_not_jump_when_dragging_to_editable_content_boundary(self, el_id):
         self.open_test_html(self._cursor_html)
-        el = self.marionette.find_element(By.ID, self._input_id)
+        el = self.marionette.find_element(By.ID, el_id)
         sel = SelectionManager(el)
         content_to_add = '!'
         non_target_content = sel.content + content_to_add
 
-        # Goal: the cursor position does not being changed after dragging the
-        # caret down on the Y-axis.
+        # Goal: the cursor position is not changed after dragging the caret down
+        # on the Y-axis.
         el.tap()
         sel.move_cursor_to_front()
         el.tap(*sel.cursor_location())
         x, y = sel.first_caret_location()
 
         # Drag the caret down by 50px, and insert '!'.
         self.actions.flick(el, x, y, x, y + 50).perform()
         self.actions.key_down(content_to_add).key_up(content_to_add).perform()
         self.assertNotEqual(non_target_content, sel.content)
 
+    @parameterized(_input_id, el_id=_input_id)
+    @parameterized(_input_padding_id, el_id=_input_padding_id)
+    @parameterized(_textarea_one_line_id, el_id=_textarea_one_line_id)
+    @parameterized(_contenteditable_id, el_id=_contenteditable_id)
+    def test_caret_not_jump_to_front_when_dragging_up_to_editable_content_boundary(self, el_id):
+        self.open_test_html(self._cursor_html)
+        el = self.marionette.find_element(By.ID, el_id)
+        sel = SelectionManager(el)
+        content_to_add = '!'
+        non_target_content = content_to_add + sel.content
+
+        # Goal: the cursor position is not changed after dragging the caret down
+        # on the Y-axis.
+        el.tap()
+        sel.move_cursor_to_end()
+        sel.move_cursor_by_offset(1, backward=True)
+        el.tap(*sel.cursor_location())
+        x, y = sel.first_caret_location()
+
+        # Drag the caret up by 50px, and insert '!'.
+        self.actions.flick(el, x, y, x, y - 50).perform()
+        self.actions.key_down(content_to_add).key_up(content_to_add).perform()
+        self.assertNotEqual(non_target_content, sel.content)
+
     def test_drag_caret_from_front_to_end_across_columns(self):
         self.open_test_html('test_carets_columns.html')
         el = self.marionette.find_element(By.ID, 'columns-inner')
         sel = SelectionManager(el)
         content_to_add = '!'
         target_content = sel.content + content_to_add
 
         # Goal: the cursor position can be changed by dragging the caret from

--- a/layout/base/tests/marionette/test_accessiblecaret_selection_mode.py
+++ b/layout/base/tests/marionette/test_accessiblecaret_selection_mode.py
@@ -20,18 +20,20 @@ def skip_if_not_rotatable(target):
         return target(self, *args, **kwargs)
     return wrapper
 
 
 class AccessibleCaretSelectionModeTestCase(MarionetteTestCase):
     '''Test cases for AccessibleCaret under selection mode.'''
     # Element IDs.
     _input_id = 'input'
+    _input_padding_id = 'input-padding'
     _textarea_id = 'textarea'
     _textarea2_id = 'textarea2'
+    _textarea_one_line_id = 'textarea-one-line'
     _textarea_rtl_id = 'textarea-rtl'
     _contenteditable_id = 'contenteditable'
     _contenteditable2_id = 'contenteditable2'
     _content_id = 'content'
     _content2_id = 'content2'
     _non_selectable_id = 'non-selectable'
 
     # Test html files.
@@ -537,30 +539,34 @@ class AccessibleCaretSelectionModeTestCa
 
         # If the second carets is visible, it can be dragged to the position of
         # the first caret. After that, selection will contain only the first
         # character.
         (caret1_x, caret1_y), (caret2_x, caret2_y) = sel.carets_location()
         self.actions.flick(el, caret2_x, caret2_y, caret1_x, caret1_y).perform()
         self.assertEqual(words[0][0], sel.selected_content)
 
-    def test_carets_do_not_jump_when_dragging_to_editable_content_boundary(self):
+    @parameterized(_input_id, el_id=_input_id)
+    @parameterized(_input_padding_id, el_id=_input_padding_id)
+    @parameterized(_textarea_one_line_id, el_id=_textarea_one_line_id)
+    @parameterized(_contenteditable_id, el_id=_contenteditable_id)
+    def test_carets_not_jump_when_dragging_to_editable_content_boundary(self, el_id):
         self.open_test_html(self._selection_html)
-        el = self.marionette.find_element(By.ID, self._input_id)
+        el = self.marionette.find_element(By.ID, el_id)
         sel = SelectionManager(el)
         original_content = sel.content
         words = original_content.split()
         self.assertTrue(len(words) >= 3, 'Expect at least three words in the content.')
 
-        # Goal: the selection does not being changed after dragging the caret
-        # on the Y-axis only.
+        # Goal: the selection is not changed after dragging the caret on the
+        # Y-axis.
         target_content = words[1]
 
         self.long_press_on_word(el, 1)
         (caret1_x, caret1_y), (caret2_x, caret2_y) = sel.carets_location()
 
         # Drag the first caret up by 50px.
         self.actions.flick(el, caret1_x, caret1_y, caret1_x, caret1_y - 50).perform()
         self.assertEqual(target_content, sel.selected_content)
 
-        # Drag the first caret down by 50px.
+        # Drag the second caret down by 50px.
         self.actions.flick(el, caret2_x, caret2_y, caret2_x, caret2_y + 50).perform()
         self.assertEqual(target_content, sel.selected_content)

--- a/testing/marionette/harness/marionette/www/test_carets_cursor.html
+++ b/testing/marionette/harness/marionette/www/test_carets_cursor.html
@@ -11,15 +11,21 @@
       width: 10em;
       height: 6em;
       word-wrap: break-word;
       overflow: auto;
     }
     </style>
   </head>
   <body>
-    <div><input id="input" value="ABCDEFGHI"></div>
+    <div>
+      <input id="input" value="ABCDEFGHI">
+      <input id="input-padding" style="padding: 1em;" value="ABCDEFGHI">
+    </div>
     <br>
-    <div><textarea name="textarea" id="textarea" rows="4" cols="6">ABCDEFGHI</textarea></div>
+    <div>
+      <textarea name="textarea" id="textarea" rows="4" cols="6">ABCDEFGHI</textarea>
+      <textarea id="textarea-one-line" rows="3">ABCDEFGHI</textarea>
+    </div>
     <br>
     <div class="block" contenteditable="true" id="contenteditable">ABCDEFGHI</div>
   </body>
 </html>

--- a/testing/marionette/harness/marionette/www/test_carets_selection.html
+++ b/testing/marionette/harness/marionette/www/test_carets_selection.html
@@ -2,31 +2,37 @@
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 <!DOCTYPE html>
 <html id="html">
   <head>
     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
     <title>Marionette tests for AccessibleCaret in selection mode</title>
+    <style>
+    .block {
+      width: 10em;
+      height: 4em;
+      word-wrap: break-word;
+      overflow: auto;
+    }
+    </style>
   </head>
   <body>
-  <style>
-  div.block {
-    width: 10em;
-    height: 4em;
-    word-wrap: break-word;
-    overflow: auto;
-  }
-  </style>
-    <div><input id="input" value="ABC DEF GHI"></div>
-    <br />
-    <div><textarea id="textarea" rows="4" cols="8">ABC DEF GHI JKL MNO PQR</textarea></div>
-    <br />
+    <div>
+      <input id="input" value="ABC DEF GHI">
+      <input id="input-padding" style="padding: 1em;" value="ABC DEF GHI">
+    </div>
+    <br>
+    <div>
+      <textarea id="textarea" rows="4" cols="8">ABC DEF GHI JKL MNO PQR</textarea>
+      <textarea id="textarea-one-line" rows="4" cols="12">ABC DEF GHI</textarea>
+    </div>
+    <br>
     <div><textarea dir="rtl" id="textarea-rtl" rows="8" cols="8">موزيلا فيرفكس موزيلا فيرفكس</textarea></div>
-    <br />
+    <br>
     <div class="block" contenteditable="true" id="contenteditable">ABC DEF GHI</div>
-    <br />
+    <br>
     <div class="block" id="content">ABC DEF GHI</div>
-    <br />
+    <br>
     <div style="-moz-user-select: none;" id="non-selectable">Non-selectable</div>
   </body>
 </html>