Merge #10946 from justinmk/vim-patchhhh

vim-patch:8.1.1498,8.1.1501: b:changedtick

8 files changed, 64 insertions, 22 deletions

diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 06f88955c9..8ec9dbdbdf 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -1313,8 +1313,10 @@ One local buffer variable is predefined:
 					*b:changedtick* *changetick*
 b:changedtick	The total number of changes to the current buffer.  It is
 		incremented for each change.  An undo command is also a change
-		in this case.  This can be used to perform an action only when
-		the buffer has changed.  Example: >
+		in this case.  Resetting 'modified' when writing the buffer is
+		also counted.
+		This can be used to perform an action only when the buffer has
+		changed.  Example: >
 		    :if my_changedtick != b:changedtick
 		    :	let my_changedtick = b:changedtick
 		    :	call My_Update()
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 382b4c45c1..6cb1da04be 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -144,7 +144,7 @@ read_buffer(
     if (!readonlymode && !BUFEMPTY()) {
       changed();
     } else if (retval != FAIL) {
-      unchanged(curbuf, false);
+      unchanged(curbuf, false, true);
     }
 
     apply_autocmds_retval(EVENT_STDINREADPOST, NULL, NULL, false,
@@ -299,7 +299,7 @@ int open_buffer(
       || (aborting() && vim_strchr(p_cpo, CPO_INTMOD) != NULL)) {
     changed();
   } else if (retval != FAIL && !read_stdin && !read_fifo) {
-    unchanged(curbuf, false);
+    unchanged(curbuf, false, true);
   }
   save_file_ff(curbuf);                 // keep this fileformat
 
@@ -641,13 +641,11 @@ void close_buffer(win_T *win, buf_T *buf, int action, int abort_if_last)
   }
 }
 
-/*
- * Make buffer not contain a file.
- */
+/// Make buffer not contain a file.
 void buf_clear_file(buf_T *buf)
 {
   buf->b_ml.ml_line_count = 1;
-  unchanged(buf, true);
+  unchanged(buf, true, true);
   buf->b_p_eol = true;
   buf->b_start_eol = true;
   buf->b_p_bomb = false;
diff --git a/src/nvim/change.c b/src/nvim/change.c
index f8a4cf4282..3401f8a0a8 100644
--- a/src/nvim/change.c
+++ b/src/nvim/change.c
@@ -478,9 +478,11 @@ changed_lines(
   }
 }
 
-/// Called when the changed flag must be reset for buffer "buf".
-/// When "ff" is true also reset 'fileformat'.
-void unchanged(buf_T *buf, int ff)
+/// Called when the changed flag must be reset for buffer `buf`.
+/// When `ff` is true also reset 'fileformat'.
+/// When `always_inc_changedtick` is true b:changedtick is incremented even
+/// when the changed flag was off.
+void unchanged(buf_T *buf, int ff, bool always_inc_changedtick)
 {
   if (buf->b_changed || (ff && file_ff_differs(buf, false))) {
     buf->b_changed = false;
@@ -491,8 +493,10 @@ void unchanged(buf_T *buf, int ff)
     check_status(buf);
     redraw_tabline = true;
     need_maketitle = true;  // set window title later
+    buf_inc_changedtick(buf);
+  } else if (always_inc_changedtick) {
+    buf_inc_changedtick(buf);
   }
-  buf_inc_changedtick(buf);
 }
 
 /// Insert string "p" at the cursor position.  Stops at a NUL byte.
diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index 691ad74100..18df168c57 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -1323,7 +1323,7 @@ void dialog_changed(buf_T *buf, bool checkall)
       (void)buf_write_all(buf, false);
     }
   } else if (ret == VIM_NO) {
-    unchanged(buf, true);
+    unchanged(buf, true, false);
   } else if (ret == VIM_ALL) {
     // Write all modified files that can be written.
     // Skip readonly buffers, these need to be confirmed
@@ -1348,7 +1348,7 @@ void dialog_changed(buf_T *buf, bool checkall)
   } else if (ret == VIM_DISCARDALL) {
     // mark all buffers as unchanged
     FOR_ALL_BUFFERS(buf2) {
-      unchanged(buf2, true);
+      unchanged(buf2, true, false);
     }
   }
 }
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 8b19257d3d..b99a254fad 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -3485,10 +3485,10 @@ restore_backup:
   if (reset_changed && whole && !append
       && !write_info.bw_conv_error
       && (overwriting || vim_strchr(p_cpo, CPO_PLUS) != NULL)) {
-    unchanged(buf, true);
+    unchanged(buf, true, false);
     const varnumber_T changedtick = buf_get_changedtick(buf);
     if (buf->b_last_changedtick + 1 == changedtick) {
-      // changedtick is always incremented in unchanged() but that
+      // b:changedtick may be incremented in unchanged() but that
       // should not trigger a TextChanged event.
       buf->b_last_changedtick = changedtick;
     }
@@ -5107,14 +5107,14 @@ void buf_reload(buf_T *buf, int orig_mode)
         }
         (void)move_lines(savebuf, buf);
       }
-    } else if (buf == curbuf) {  /* "buf" still valid */
-      /* Mark the buffer as unmodified and free undo info. */
-      unchanged(buf, TRUE);
+    } else if (buf == curbuf) {  // "buf" still valid.
+      // Mark the buffer as unmodified and free undo info.
+      unchanged(buf, true, true);
       if ((flags & READ_KEEP_UNDO) == 0) {
         u_blockfree(buf);
         u_clearall(buf);
       } else {
-        /* Mark all undo states as changed. */
+        // Mark all undo states as changed.
         u_unchanged(curbuf);
       }
     }
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index b69812a389..15dd2767a2 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -1003,7 +1003,7 @@ void ml_recover(void)
     set_option_value("fenc", 0L, (char *)b0_fenc, OPT_LOCAL);
     xfree(b0_fenc);
   }
-  unchanged(curbuf, TRUE);
+  unchanged(curbuf, true, true);
 
   bnum = 1;             /* start with block 1 */
   page_count = 1;       /* which is 1 page */
diff --git a/src/nvim/testdir/test_changedtick.vim b/src/nvim/testdir/test_changedtick.vim
index 3a91bb54aa..c789cdc1bc 100644
--- a/src/nvim/testdir/test_changedtick.vim
+++ b/src/nvim/testdir/test_changedtick.vim
@@ -55,3 +55,41 @@ func Test_changedtick_fixed()
   call assert_fails('unlet d["changedtick"]', 'E46:')
 
 endfunc
+
+func Test_changedtick_not_incremented_with_write()
+  new
+  let fname = "XChangeTick"
+  exe 'w ' .. fname
+
+  " :write when the buffer is not changed does not increment changedtick
+  let expected = b:changedtick
+  w
+  call assert_equal(expected, b:changedtick)
+
+  " :write when the buffer IS changed DOES increment changedtick
+  let expected = b:changedtick + 1
+  setlocal modified
+  w
+  call assert_equal(expected, b:changedtick)
+
+  " Two ticks: change + write
+  let expected = b:changedtick + 2
+  call setline(1, 'hello')
+  w
+  call assert_equal(expected, b:changedtick)
+
+  " Two ticks: start insert + write
+  let expected = b:changedtick + 2
+  normal! o
+  w
+  call assert_equal(expected, b:changedtick)
+
+  " Three ticks: start insert + change + write
+  let expected = b:changedtick + 3
+  normal! ochanged
+  w
+  call assert_equal(expected, b:changedtick)
+
+  bwipe
+  call delete(fname)
+endfunc
diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index c8343941d2..8ec36a8fe3 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -2294,7 +2294,7 @@ static void u_undoredo(int undo, bool do_buf_event)
   if (old_flags & UH_CHANGED) {
     changed();
   } else {
-    unchanged(curbuf, FALSE);
+    unchanged(curbuf, false, true);
   }
 
   // because the calls to changed()/unchanged() above will bump changedtick