Inherit text props in Completion Preview insertion commands

When completing with Completion Preview mode commands,
inherit text properties from surrounding text similarly to
other completion commands, such as 'completion-at-point'.

* lisp/completion-preview.el (completion-preview-insert)
(completion-preview-partial-insert)
(completion-preview-complete): Use 'insert-and-inherit'
instead of 'insert' to insert text for completion.
* test/lisp/completion-preview-tests.el
(completion-preview-insert-inherits-text-properties): New
test.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/lisp/completion-preview-tests.el b/test/lisp/completion-preview-tests.el
index 95985470479..b190ecb7020 100644
--- a/test/lisp/completion-preview-tests.el
+++ b/test/lisp/completion-preview-tests.el
@@ -432,4 +432,17 @@ instead."
       (should-not exit-fn-called)
       (should-not exit-fn-args))))
 
+(ert-deftest completion-preview-insert-inherits-text-properties ()
+  "Test that `completion-preview-insert' inherits text properties."
+  (with-temp-buffer
+    (setq-local completion-at-point-functions
+                (list (completion-preview-tests--capf '("foobar" "foobaz"))))
+    (insert (propertize "foo" 'prop 'val))
+    (let ((this-command 'self-insert-command))
+      (completion-preview--post-command))
+    (completion-preview-tests--check-preview "bar" 'completion-preview-common)
+    (completion-preview-insert)
+    (should (string= (buffer-string) "foobar"))
+    (should (eq (get-text-property 6 'prop) 'val))))
+
 ;;; completion-preview-tests.el ends here