Remove 'n' flag from ending part of comments (whonore#307)

Fixes whonore#305, whonore#306

I'm not 100% sure why this works, or whether the flag is actually doing anything useful in the comment opener, but I'll leave it for now.

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 ## Unreleased ([master])
 
+### Fixed
+- Joining comments with `J` while the `j` flag is set in `'formatoptions'` does
+  not delete the second line.
+  (PR #307)
+- Formatting long comments (e.g., with `gqq`) does not stop after the second line.
+  (PR #307)
+
 ## [1.6.4]
 
 ### Added

ftplugin/coq.vim

@@ -13,7 +13,7 @@ endif
 " Comments
 if has('comments')
   setlocal commentstring=(*%s*)
-  setlocal comments=srn:(*,mb:*,exn:*)
+  setlocal comments=srn:(*,mb:*,ex:*)
   " NOTE: The 'r' and 'o' flags mistake the '*' bullet as a middle comment and
   " will automatically add an extra one after <Enter>, 'o' or 'O'.
   setlocal formatoptions-=t formatoptions-=r formatoptions-=o formatoptions+=cql

tests/vim/comments.vader

@@ -0,0 +1,28 @@
+" Author: Wolf Honore
+" Coq comment formatting unit tests.
+
+Before:
+  set textwidth=40
+  set formatoptions+=qj
+
+Given coq (join-comment):
+  (* Lorem ipsum dolor sit amet,
+   * consectetur adipiscing elit. *)
+
+Do (join-comment):
+  J
+
+Expect coq (join-comment):
+  (* Lorem ipsum dolor sit amet, consectetur adipiscing elit. *)
+
+Given coq (format-long-comment):
+  (* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam eleifend mauris et lectus rhoncus, at feugiat sapien euismod. *)
+
+Do (format-long-comment):
+  gqq
+
+Expect coq (format-long-comment):
+  (* Lorem ipsum dolor sit amet,
+   * consectetur adipiscing elit. Nam
+   * eleifend mauris et lectus rhoncus, at
+   * feugiat sapien euismod. *)