patch 8.1.1326: no test for listener with partial

Problem:    No test for listener with partial.
Solution:   Add a test.  Add example to help.

runtime/doc/eval.txt

@@ -6323,7 +6323,8 @@ listener_add({callback} [, {buf}])			*listener_add()*
 		Returns a unique ID that can be passed to |listener_remove()|.
 
 		The {callback} is invoked with a list of items that indicate a
-		change.  Each list item is a dictionary with these entries:
+		change.  The list cannot be changed.  Each list item is a
+		dictionary with these entries:
 		    lnum	the first line number of the change
 		    end		the first line below the change
 		    added	number of lines added; negative if lines were
@@ -6349,7 +6350,21 @@ listener_add({callback} [, {buf}])			*listener_add()*
 		    added	zero
 		    col		first column with a change or one
 
-		The {callback} is invoked just before the screen is updated.
+		The entries are in the order the changes was made, thus the
+		most recent change is at the end.  One has to go through the
+		list from end to start to compute the line numbers in the
+		current state of the text.
+
+		When using the same function for multiple buffers, you can
+		pass the buffer to that function using a |Partial|.
+		Example: >
+		    func Listener(bufnr, changes)
+		      " ...
+		    endfunc
+		    let bufnr = ...
+		    call listener_add(function('Listener', [bufnr]), bufnr)
+
+<		The {callback} is invoked just before the screen is updated.
 		To trigger this in a script use the `:redraw` command.
 
 		The {callback} is not invoked when the buffer is first loaded.
@@ -10984,10 +10999,10 @@ expressions |expr-lambda|.
 
 Example: >
   function Something(key, value = 10)
-     echo a:key .. ": " .. value
+     echo a:key .. ": " .. a:value
   endfunction
   call Something('empty')	"empty: 10"
-  call Something('key, 20)	"key: 20"
+  call Something('key', 20)	"key: 20"
 
 The argument default expressions are evaluated at the time of the function
 call, not definition.  Thus it is possible to use an expression which is

src/testdir/test_listener.vim

@@ -1,77 +1,86 @@
 " tests for listener_add() and listener_remove()
 
-func StoreList(l)
+func s:StoreList(l)
-  let g:list = a:l
+  let s:list = a:l
 endfunc
 
-func AnotherStoreList(l)
+func s:AnotherStoreList(l)
-  let g:list2 = a:l
+  let s:list2 = a:l
 endfunc
 
-func EvilStoreList(l)
+func s:EvilStoreList(l)
-  let g:list3 = a:l
+  let s:list3 = a:l
   call assert_fails("call add(a:l, 'myitem')", "E742:")
 endfunc
 
 func Test_listening()
   new
   call setline(1, ['one', 'two'])
-  let id = listener_add({l -> StoreList(l)})
+  let id = listener_add({l -> s:StoreList(l)})
   call setline(1, 'one one')
   redraw
-  call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], g:list)
+  call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], s:list)
 
   " Two listeners, both get called.
-  let id2 = listener_add({l -> AnotherStoreList(l)})
+  let id2 = listener_add({l -> s:AnotherStoreList(l)})
-  let g:list = []
+  let s:list = []
-  let g:list2 = []
+  let s:list2 = []
   exe "normal $asome\<Esc>"
   redraw
-  call assert_equal([{'lnum': 1, 'end': 2, 'col': 8, 'added': 0}], g:list)
+  call assert_equal([{'lnum': 1, 'end': 2, 'col': 8, 'added': 0}], s:list)
-  call assert_equal([{'lnum': 1, 'end': 2, 'col': 8, 'added': 0}], g:list2)
+  call assert_equal([{'lnum': 1, 'end': 2, 'col': 8, 'added': 0}], s:list2)
 
   call listener_remove(id2)
-  let g:list = []
+  let s:list = []
-  let g:list2 = []
+  let s:list2 = []
   call setline(3, 'three')
   redraw
-  call assert_equal([{'lnum': 3, 'end': 3, 'col': 1, 'added': 1}], g:list)
+  call assert_equal([{'lnum': 3, 'end': 3, 'col': 1, 'added': 1}], s:list)
-  call assert_equal([], g:list2)
+  call assert_equal([], s:list2)
 
   " the "o" command first adds an empty line and then changes it
-  let g:list = []
+  let s:list = []
   exe "normal Gofour\<Esc>"
   redraw
   call assert_equal([{'lnum': 4, 'end': 4, 'col': 1, 'added': 1},
-	\ {'lnum': 4, 'end': 5, 'col': 1, 'added': 0}], g:list)
+	\ {'lnum': 4, 'end': 5, 'col': 1, 'added': 0}], s:list)
 
-  let g:list = []
+  " Remove last listener
+  let s:list = []
   call listener_remove(id)
   call setline(1, 'asdfasdf')
   redraw
-  call assert_equal([], g:list)
+  call assert_equal([], s:list)
 
   " Trying to change the list fails
-  let id = listener_add({l -> EvilStoreList(l)})
+  let id = listener_add({l -> s:EvilStoreList(l)})
-  let g:list3 = []
+  let s:list3 = []
   call setline(1, 'asdfasdf')
   redraw
-  call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], g:list3)
+  call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], s:list3)
 
+  call listener_remove(id)
   bwipe!
 endfunc
 
+func s:StoreBufList(buf, l)
+  let s:bufnr = a:buf
+  let s:list = a:l
+endfunc
+
 func Test_listening_other_buf()
   new
   call setline(1, ['one', 'two'])
   let bufnr = bufnr('')
   normal ww
-  let id = listener_add({l -> StoreList(l)}, bufnr)
+  let id = listener_add(function('s:StoreBufList', [bufnr]), bufnr)
-  let g:list = []
+  let s:list = []
   call setbufline(bufnr, 1, 'hello')
   redraw
-  call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], g:list)
+  call assert_equal(bufnr, s:bufnr)
+  call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], s:list)
 
+  call listener_remove(id)
   exe "buf " .. bufnr
   bwipe!
 endfunc

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1326,
 /**/
     1325,
 /**/