* test/lisp/vc/diff-mode-tests.el (diff-mode-test-font-lock): New test.

(diff-mode-test-font-lock-syntax-one-line): New test for one line.

* test/data/vc/diff-mode/hello_world.c:
* test/data/vc/diff-mode/hello_world_1.c:
* test/data/vc/diff-mode/hello_emacs.c:
* test/data/vc/diff-mode/hello_emacs_1.c: New fixtures.

* lisp/vc/diff-mode.el (diff-syntax-fontify): Move remove-overlays
from diff-syntax-fontify-hunk.  (Bug#33567)
(diff-syntax-fontify-hunk): Remove VISIT arg from insert-file-contents.

4 files changed, 14 insertions, 0 deletions

diff --git a/test/data/vc/diff-mode/hello_emacs.c b/test/data/vc/diff-mode/hello_emacs.c
new file mode 100644
index 00000000000..c7ed7538c3a
--- /dev/null
+++ b/test/data/vc/diff-mode/hello_emacs.c
@@ -0,0 +1,6 @@
+#include <stdio.h>
+int main()
+{
+  printf("Hello, Emacs!\n");
+  return 0;
+}
diff --git a/test/data/vc/diff-mode/hello_emacs_1.c b/test/data/vc/diff-mode/hello_emacs_1.c
new file mode 100644
index 00000000000..62145a6b44a
--- /dev/null
+++ b/test/data/vc/diff-mode/hello_emacs_1.c
@@ -0,0 +1 @@
+int main() { printf("Hello, Emacs!\n"); return 0; }
\ No newline at end of file
diff --git a/test/data/vc/diff-mode/hello_world.c b/test/data/vc/diff-mode/hello_world.c
new file mode 100644
index 00000000000..dcbe06c6012
--- /dev/null
+++ b/test/data/vc/diff-mode/hello_world.c
@@ -0,0 +1,6 @@
+#include <stdio.h>
+int main()
+{
+  printf("Hello, World!\n");
+  return 0;
+}
diff --git a/test/data/vc/diff-mode/hello_world_1.c b/test/data/vc/diff-mode/hello_world_1.c
new file mode 100644
index 00000000000..606afb371cb
--- /dev/null
+++ b/test/data/vc/diff-mode/hello_world_1.c
@@ -0,0 +1 @@
+int main() { printf("Hello, World!\n"); return 0; }
\ No newline at end of file