vim-patch:8.2.0018: :join does not add white space where it should

Problem:    :join does not add white space where it should. (Zdenek Dohnal)
Solution:   Handle joining multiple lines propely.
https://github.com/vim/vim/commit/91b65e49440e77222a65b6f868507453239f409b

2 files changed, 386 insertions, 1 deletions

diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index 294c65ca03..0ca16e2c25 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -3772,7 +3772,7 @@ int do_join(size_t count,
       curr = skipwhite(curr);
       if (*curr != NUL
           && *curr != ')'
-          && currsize != 0
+          && sumsize != 0
           && endcurr1 != TAB
           && (!has_format_option(FO_MBYTE_JOIN)
               || (utf_ptr2char(curr) < 0x100 && endcurr1 < 0x100))
diff --git a/src/nvim/testdir/test_join.vim b/src/nvim/testdir/test_join.vim
index ecb55c9af6..ac6ef8f29f 100644
--- a/src/nvim/testdir/test_join.vim
+++ b/src/nvim/testdir/test_join.vim
@@ -54,3 +54,388 @@ func Test_join_marks()
   call assert_equal([0, 4, 67, 0], getpos("']"))
   enew!
 endfunc
+
+" Test for joining lines and marks in them
+"   in compatible and nocompatible modes
+"   and with 'joinspaces' set or not
+"   and with 'cpoptions' flag 'j' set or not
+func Test_join_spaces_marks()
+  new
+  " Text used for the test
+  insert
+asdfasdf.
+asdf
+asdfasdf. 
+asdf
+asdfasdf.  
+asdf
+asdfasdf.	
+asdf
+asdfasdf. 	
+asdf
+asdfasdf.	 
+asdf
+asdfasdf.		
+asdf
+asdfasdf
+asdf
+asdfasdf 
+asdf
+asdfasdf  
+asdf
+asdfasdf	
+asdf
+asdfasdf	 
+asdf
+asdfasdf 	
+asdf
+asdfasdf		
+asdf
+zx cvn.
+as dfg?
+hjkl iop!
+ert
+zx cvn.
+as dfg?
+hjkl iop!
+ert
+.
+  let text = getline(1, '$')
+  normal gg
+
+  set nojoinspaces
+  set cpoptions-=j
+  normal JjJjJjJjJjJjJjJjJjJjJjJjJjJ
+  normal j05lmx
+  normal 2j06lmy
+  normal 2k4Jy3l$p
+  normal `xyl$p
+  normal `yy2l$p
+
+  " set cpoptions+=j
+  normal j05lmx
+  normal 2j06lmy
+  normal 2k4Jy3l$p
+  normal `xyl$p
+  normal `yy2l$p
+
+  " Expected output
+  let expected =<< trim [DATA]
+    asdfasdf. asdf
+    asdfasdf. asdf
+    asdfasdf.  asdf
+    asdfasdf.	asdf
+    asdfasdf. 	asdf
+    asdfasdf.	 asdf
+    asdfasdf.		asdf
+    asdfasdf asdf
+    asdfasdf asdf
+    asdfasdf  asdf
+    asdfasdf	asdf
+    asdfasdf	 asdf
+    asdfasdf 	asdf
+    asdfasdf		asdf
+    zx cvn. as dfg? hjkl iop! ert ernop
+    zx cvn. as dfg? hjkl iop! ert ernop
+  [DATA]
+
+  call assert_equal(expected, getline(1, '$'))
+  throw 'skipped: Nvim does not support "set compatible" or "set cpoptions+=j"'
+
+  enew!
+  call append(0, text)
+  normal gg
+
+  set cpoptions-=j
+  set joinspaces
+  normal JjJjJjJjJjJjJjJjJjJjJjJjJjJ
+  normal j05lmx
+  normal 2j06lmy
+  normal 2k4Jy3l$p
+  normal `xyl$p
+  normal `yy2l$p
+
+  set cpoptions+=j
+  normal j05lmx
+  normal 2j06lmy
+  normal 2k4Jy3l$p
+  normal `xyl$p
+  normal `yy2l$p
+
+  " Expected output
+  let expected =<< trim [DATA]
+    asdfasdf.  asdf
+    asdfasdf.  asdf
+    asdfasdf.  asdf
+    asdfasdf.	asdf
+    asdfasdf. 	asdf
+    asdfasdf.	 asdf
+    asdfasdf.		asdf
+    asdfasdf asdf
+    asdfasdf asdf
+    asdfasdf  asdf
+    asdfasdf	asdf
+    asdfasdf	 asdf
+    asdfasdf 	asdf
+    asdfasdf		asdf
+    zx cvn.  as dfg?  hjkl iop!  ert  enop
+    zx cvn.  as dfg? hjkl iop! ert ernop
+
+  [DATA]
+
+  call assert_equal(expected, getline(1, '$'))
+
+  enew!
+  call append(0, text)
+  normal gg
+
+  set cpoptions-=j
+  set nojoinspaces
+  set compatible
+
+  normal JjJjJjJjJjJjJjJjJjJjJjJjJjJ
+  normal j4Jy3l$pjdG
+
+  " Expected output
+  let expected =<< trim [DATA]
+    asdfasdf.  asdf
+    asdfasdf.  asdf
+    asdfasdf.  asdf
+    asdfasdf.	asdf
+    asdfasdf. 	asdf
+    asdfasdf.	 asdf
+    asdfasdf.		asdf
+    asdfasdf asdf
+    asdfasdf asdf
+    asdfasdf  asdf
+    asdfasdf	asdf
+    asdfasdf	 asdf
+    asdfasdf 	asdf
+    asdfasdf		asdf
+    zx cvn.  as dfg? hjkl iop! ert  a
+  [DATA]
+
+  call assert_equal(expected, getline(1, '$'))
+
+  set nocompatible
+  set cpoptions&vim
+  set joinspaces&vim
+  close!
+endfunc
+
+" Test for joining lines with comments
+func Test_join_lines_with_comments()
+  new
+
+  " Text used by the test
+  insert
+{
+
+/*
+* Make sure the previous comment leader is not removed.
+*/
+
+/*
+* Make sure the previous comment leader is not removed.
+*/
+
+// Should the next comment leader be left alone?
+// Yes.
+
+// Should the next comment leader be left alone?
+// Yes.
+
+/* Here the comment leader should be left intact. */
+// And so should this one.
+
+/* Here the comment leader should be left intact. */
+// And so should this one.
+
+if (condition) // Remove the next comment leader!
+// OK, I will.
+action();
+
+if (condition) // Remove the next comment leader!
+// OK, I will.
+action();
+}
+.
+
+  call cursor(2, 1)
+  set comments=s1:/*,mb:*,ex:*/,://
+  set nojoinspaces fo=j
+  set backspace=eol,start
+
+  .,+3join
+  exe "normal j4J\<CR>"
+  .,+2join
+  exe "normal j3J\<CR>"
+  .,+2join
+  exe "normal j3J\<CR>"
+  .,+2join
+  exe "normal jj3J\<CR>"
+
+  " Expected output
+  let expected =<< trim [CODE]
+    {
+    /* Make sure the previous comment leader is not removed. */
+    /* Make sure the previous comment leader is not removed. */
+    // Should the next comment leader be left alone? Yes.
+    // Should the next comment leader be left alone? Yes.
+    /* Here the comment leader should be left intact. */ // And so should this one.
+    /* Here the comment leader should be left intact. */ // And so should this one.
+    if (condition) // Remove the next comment leader! OK, I will.
+    action();
+    if (condition) // Remove the next comment leader! OK, I will.
+    action();
+    }
+  [CODE]
+
+  call assert_equal(expected, getline(1, '$'))
+
+  set comments&vim
+  set joinspaces&vim
+  set fo&vim
+  set backspace&vim
+  close!
+endfunc
+
+" Test for joining lines with different comment leaders
+func Test_join_comments_2()
+  new
+
+  insert
+{
+
+/*
+ * Make sure the previous comment leader is not removed.
+ */
+
+/*
+ * Make sure the previous comment leader is not removed.
+ */
+
+/* List:
+ * - item1
+ *   foo bar baz
+ *   foo bar baz
+ * - item2
+ *   foo bar baz
+ *   foo bar baz
+ */
+
+/* List:
+ * - item1
+ *   foo bar baz
+ *   foo bar baz
+ * - item2
+ *   foo bar baz
+ *   foo bar baz
+ */
+
+// Should the next comment leader be left alone?
+// Yes.
+
+// Should the next comment leader be left alone?
+// Yes.
+
+/* Here the comment leader should be left intact. */
+// And so should this one.
+
+/* Here the comment leader should be left intact. */
+// And so should this one.
+
+if (condition) // Remove the next comment leader!
+               // OK, I will.
+    action();
+
+if (condition) // Remove the next comment leader!
+               // OK, I will.
+    action();
+
+int i = 7 /* foo *// 3
+ // comment
+ ;
+
+int i = 7 /* foo *// 3
+ // comment
+ ;
+
+># Note that the last character of the ending comment leader (left angle
+ # bracket) is a comment leader itself. Make sure that this comment leader is
+ # not removed from the next line #<
+< On this line a new comment is opened which spans 2 lines. This comment should
+< retain its comment leader.
+
+># Note that the last character of the ending comment leader (left angle
+ # bracket) is a comment leader itself. Make sure that this comment leader is
+ # not removed from the next line #<
+< On this line a new comment is opened which spans 2 lines. This comment should
+< retain its comment leader.
+
+}
+.
+
+  call cursor(2, 1)
+  set comments=sO:*\ -,mO:*\ \ ,exO:*/
+  set comments+=s1:/*,mb:*,ex:*/,://
+  set comments+=s1:>#,mb:#,ex:#<,:<
+  set cpoptions-=j joinspaces fo=j
+  set backspace=eol,start
+
+  .,+3join
+  exe "normal j4J\<CR>"
+  .,+8join
+  exe "normal j9J\<CR>"
+  .,+2join
+  exe "normal j3J\<CR>"
+  .,+2join
+  exe "normal j3J\<CR>"
+  .,+2join
+  exe "normal jj3J\<CR>j"
+  .,+2join
+  exe "normal jj3J\<CR>j"
+  .,+5join
+  exe "normal j6J\<CR>"
+  exe "normal oSome code!\<CR>// Make sure backspacing does not remove this comment leader.\<Esc>0i\<C-H>\<Esc>"
+
+  " Expected output
+  let expected =<< trim [CODE]
+    {
+    /* Make sure the previous comment leader is not removed.  */
+    /* Make sure the previous comment leader is not removed.  */
+    /* List: item1 foo bar baz foo bar baz item2 foo bar baz foo bar baz */
+    /* List: item1 foo bar baz foo bar baz item2 foo bar baz foo bar baz */
+    // Should the next comment leader be left alone?  Yes.
+    // Should the next comment leader be left alone?  Yes.
+    /* Here the comment leader should be left intact. */ // And so should this one.
+    /* Here the comment leader should be left intact. */ // And so should this one.
+    if (condition) // Remove the next comment leader!  OK, I will.
+        action();
+    if (condition) // Remove the next comment leader!  OK, I will.
+        action();
+    int i = 7 /* foo *// 3 // comment
+     ;
+    int i = 7 /* foo *// 3 // comment
+     ;
+    ># Note that the last character of the ending comment leader (left angle bracket) is a comment leader itself. Make sure that this comment leader is not removed from the next line #< < On this line a new comment is opened which spans 2 lines. This comment should retain its comment leader.
+    ># Note that the last character of the ending comment leader (left angle bracket) is a comment leader itself. Make sure that this comment leader is not removed from the next line #< < On this line a new comment is opened which spans 2 lines. This comment should retain its comment leader.
+    
+    Some code!// Make sure backspacing does not remove this comment leader.
+    }
+  [CODE]
+
+  call assert_equal(expected, getline(1, '$'))
+  close!
+endfunc
+
+func Test_join_lines()
+  new
+  call setline(1, ['a', 'b', '', 'c', 'd'])
+  %join
+  call assert_equal('a b c d', getline(1))
+  call setline(1, ['a', 'b', '', 'c', 'd'])
+  normal 5J
+  call assert_equal('a b c d', getline(1))
+  bwipe!
+endfunc