patch 9.1.0993: New 'cmdheight' behavior may be surprising

Problem:  Although patch 9.1.0990 fixed a real problem/inconsistency,
          it also introduced new behavior that may break BWC and/or be
          unexpected. Before 9.1.0990, window commands could make the
          topframe smaller (without changing 'cmdheight'; quirk that is
          now fixed), but did not allow extending the topframe beyond
          the 'cmdheight' set by the user. After 9.1.0990, the user can
          reduce the 'cmdheight' below the value they set explicitly,
          through window commands, which may lead to confusion.
          (aftere v9.1.0990)
Solution: Store the value explicitly set by the user and clamp the
          'cmdheight' when resizing the topframe. This also applies to
          dragging laststatus, which in contrast to window commands
          _did_ allow reducing the 'cmdheight' to values below the one
          set by the user. So with this patch there is still new
          behavior, but I think in a way that is less surprising.
          While at it, also fix a Coverity warning, introduced in
          v9.1.0990 (Luuk van Baal)

closes: #16385

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/src/testdir/dumps/Test_changing_cmdheight_3.dump b/src/testdir/dumps/Test_changing_cmdheight_3.dump
index d652cc63102f61b81e172e9030fd5a73af572bde..0adb5c6664b220a2892f6055cba68e8eef323353 100644 (file)
--- a/src/testdir/dumps/Test_changing_cmdheight_3.dump
+++ b/src/testdir/dumps/Test_changing_cmdheight_3.dump
@@ -1,8 +1,8 @@
 > +0&#ffffff0@74
-|~+0#4040ff13&| @73
-|[+3#0000000&|N|o| |N|a|m|e|]| @47|0|,|0|-|1| @9|A|l@1
+|[+3&&|N|o| |N|a|m|e|]| @47|0|,|0|-|1| @9|A|l@1
 | +0&&@74
 @75
 @75
 @75
 @75
+@75

diff --git a/src/testdir/dumps/Test_changing_cmdheight_8.dump b/src/testdir/dumps/Test_changing_cmdheight_8.dump
new file mode 100644 (file)
index 0000000..1b24f33
--- /dev/null
+++ b/src/testdir/dumps/Test_changing_cmdheight_8.dump
@@ -0,0 +1,8 @@
+> +0&#ffffff0@74
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|[+3#0000000&|N|o| |N|a|m|e|]| @47|0|,|0|-|1| @9|A|l@1
+|:+0&&|w|i|n|c|m|d| |_| @65
+@75

diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 2b81dc05a9cdff54dffa19bf2c65d41770c77a3d..dfebb400b53644b91aaf85c20289097b570399a3 100644 (file)
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -293,14 +293,13 @@ func Test_changing_cmdheight()
   " :resize now also changes 'cmdheight' accordingly
   call term_sendkeys(buf, ":set cmdheight+=1\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_2', {})
-  call term_sendkeys(buf, ":set cmdheight-=1\<CR>")
 
   " using more space moves the status line up
   call term_sendkeys(buf, ":set cmdheight+=1\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_3', {})
 
   " reducing cmdheight moves status line down
-  call term_sendkeys(buf, ":set cmdheight-=2\<CR>")
+  call term_sendkeys(buf, ":set cmdheight-=3\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_4', {})
 
   " reducing window size and then setting cmdheight
@@ -312,10 +311,14 @@ func Test_changing_cmdheight()
   call term_sendkeys(buf, ":call EchoTwo()\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_6', {})
 
-  " decreasing 'cmdheight' doesn't clear the messages that need hit-enter
+  " increasing 'cmdheight' doesn't clear the messages that need hit-enter
   call term_sendkeys(buf, ":call EchoOne()\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_7', {})
 
+  " window commands do not reduce 'cmdheight' to value lower than :set by user
+  call term_sendkeys(buf, "\<CR>:wincmd _\<CR>")
+  call VerifyScreenDump(buf, 'Test_changing_cmdheight_8', {})
+
   " clean up
   call StopVimInTerminal(buf)
 endfunc

diff --git a/src/version.c b/src/version.c
index e8feb96f40159da11b1a1286411c775c7f77abdc..60de70238c7d254250b94014bbb55c01528aeb7f 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    993,
 /**/
     992,
 /**/

diff --git a/src/window.c b/src/window.c
index 93b0a327d64946e679472f8c426b1ac0a61a99b7..b15ad3eca8379682392f6afd5198b79731408958 100644 (file)
--- a/src/window.c
+++ b/src/window.c
@@ -3832,6 +3832,10 @@ frame_has_win(frame_T *frp, win_T *wp)
     return FALSE;
 }
 
+// 'cmdheight' value explicitly set by the user: window commands are allowed to
+// resize the topframe to values higher than this minimum, but not lower.
+static int min_set_ch = 1;
+
 /*
  * Set a new height for a frame.  Recursively sets the height for contained
  * frames and windows.  Caller must take care of positions.
@@ -3852,9 +3856,11 @@ frame_new_height(
     if (topfrp->fr_parent == NULL && set_ch)
     {
        // topframe: update the command line height, with side effects.
-       int new_ch = MAX(1, p_ch + topfrp->fr_height - height);
+       int new_ch = MAX(min_set_ch, p_ch + topfrp->fr_height - height);
+       int save_ch = min_set_ch;
        if (new_ch != p_ch)
            set_option_value((char_u *)"cmdheight", new_ch, NULL, 0);
+       min_set_ch = save_ch;
        height = MIN(height, ROWS_AVAIL);
     }
     if (topfrp->fr_win != NULL)
@@ -7306,7 +7312,7 @@ command_height(void)
        old_p_ch += h;
        frp = frp->fr_prev;
     }
-    if (p_ch < old_p_ch && command_frame_height)
+    if (p_ch < old_p_ch && command_frame_height && frp != NULL)
        frame_add_height(frp, (int)(old_p_ch - p_ch));
 
     // Recompute window positions.
@@ -7325,6 +7331,7 @@ command_height(void)
     // GUI starts up, we can't be sure in what order things happen.  And when
     // p_ch was changed in another tab page.
     curtab->tp_ch_used = p_ch;
+    min_set_ch = p_ch;
 }
 
 /*