[Tests][Diff][Added] using stash strategy

And this test was originally designed for a stash case

tests/test_plot/test_misc.py

@@ -1494,7 +1494,7 @@ def test_diff_git_2(test_dir):
 def test_diff_git_3(test_dir):
     """ Difference between the two repo points, no changes to stash """
     prj = 'light_control'
-    yaml = 'diff_git_2'
+    yaml = 'diff_git_3'
     ctx = context.TestContext(test_dir, prj, yaml)
     # Create a git repo
     git_init(ctx)
@@ -1826,6 +1826,7 @@ def test_definitions_1(test_dir):
 @pytest.mark.slow
 @pytest.mark.skipif(not context.ki7(), reason="Just testing with 7")
 def test_populate_1(test_dir):
+    """ Using PcbDraw as renderer """
     prj = 'simple_2layer'  # Fake
     ctx = context.TestContext(test_dir, prj, 'populate', 'Populate')
     ctx.run(no_board_file=True, extra=['-b', 'tests/data/ArduinoLearningKitStarter.kicad_pcb', 'Populate'])
@@ -1836,6 +1837,7 @@ def test_populate_1(test_dir):
 @pytest.mark.slow
 @pytest.mark.skipif(not context.ki7(), reason="Just testing with 7")
 def test_populate_2(test_dir):
+    """ Using Blender as renderer """
     prj = 'simple_2layer'  # Fake
     ctx = context.TestContext(test_dir, prj, 'populate_blender', 'PopulateSimple')
     ctx.run(no_board_file=True, extra=['-b', 'tests/data/ArduinoLearningKitStarter.kicad_pcb'])

tests/yaml_samples/diff_git_3.kibot.yaml

@@ -0,0 +1,29 @@
+kibot:
+  version: 1
+
+globals:
+  git_diff_strategy: stash
+
+outputs:
+  - name: 'diff_pcb'
+    comment: "PCB difference with git HEAD"
+    type: diff
+    layers: ['F.Cu', 'In1.Cu']
+    options:
+      old: KIBOT_LAST-1
+      old_type: git
+      new: HEAD
+      new_type: git
+      cache_dir: .cache
+      force_checkout: true
+      add_link_id: true
+
+  - name: result
+    comment: Test zip link
+    type: compress
+    options:
+      format: TAR
+      compression: lzma
+      follow_links: false
+      files:
+        - source: '*.pdf'