diff --git a/src/testdir/test_buffer.vim b/src/testdir/test_buffer.vim
index 3266adc..76fb04b 100644
--- a/src/testdir/test_buffer.vim
+++ b/src/testdir/test_buffer.vim
@@ -144,6 +144,7 @@
 func Test_bdelete_cmd()
   %bwipe!
   call assert_fails('bdelete 5', 'E516:')
+  call assert_fails('1,1bdelete 1 2', 'E488:')
 
   " Deleting a unlisted and unloaded buffer
   edit Xfile1
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index fbc6dc1..5cae272 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -255,9 +255,10 @@
   call assert_fails('set regexpengine=3', 'E474:')
   call assert_fails('set history=10001', 'E474:')
   call assert_fails('set numberwidth=21', 'E474:')
-  call assert_fails('set colorcolumn=-a')
-  call assert_fails('set colorcolumn=a')
-  call assert_fails('set colorcolumn=1,')
+  call assert_fails('set colorcolumn=-a', 'E474:')
+  call assert_fails('set colorcolumn=a', 'E474:')
+  call assert_fails('set colorcolumn=1,', 'E474:')
+  call assert_fails('set colorcolumn=1;', 'E474:')
   call assert_fails('set cmdheight=-1', 'E487:')
   call assert_fails('set cmdwinheight=-1', 'E487:')
   if has('conceal')
@@ -293,9 +294,13 @@
     call assert_fails('set guicursor=i-ci,r-cr:h', 'E545:')
     call assert_fails('set guicursor=i-ci', 'E545:')
     call assert_fails('set guicursor=x', 'E545:')
+    call assert_fails('set guicursor=x:', 'E546:')
     call assert_fails('set guicursor=r-cr:horx', 'E548:')
     call assert_fails('set guicursor=r-cr:hor0', 'E549:')
   endif
+  if has('mouseshape')
+    call assert_fails('se mouseshape=i-r:x', 'E547:')
+  endif
   call assert_fails('set backupext=~ patchmode=~', 'E589:')
   call assert_fails('set winminheight=10 winheight=9', 'E591:')
   call assert_fails('set winminwidth=10 winwidth=9', 'E592:')
diff --git a/src/testdir/test_tcl.vim b/src/testdir/test_tcl.vim
index c2fd191..d25c7f1 100644
--- a/src/testdir/test_tcl.vim
+++ b/src/testdir/test_tcl.vim
@@ -653,6 +653,9 @@
 
 " Test exiting current Tcl interpreter and re-creating one.
 func Test_tcl_exit()
+  call assert_fails('tcl exit 1 1', 'wrong # args: should be "exit ?returnCode?"')
+  call assert_fails('tcl exit x', 'expected integer but got "x"')
+
   tcl set foo "foo"
   call assert_fails('tcl exit 3', 'E572: exit code 3')
 
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index c922bea..f83ca51 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -2330,6 +2330,10 @@
   unlet! g:called_arg
 endfunc
 
+func Test_terminal_invalid_arg()
+  call assert_fails('terminal ++xyz', 'E181:')
+endfunc
+
 func Test_terminal_in_popup()
   CheckRunVimInTerminal
 
diff --git a/src/testdir/test_window_cmd.vim b/src/testdir/test_window_cmd.vim
index ceba4be..5519ffd 100644
--- a/src/testdir/test_window_cmd.vim
+++ b/src/testdir/test_window_cmd.vim
@@ -174,6 +174,35 @@
   %bw!
 endfunc
 
+func Test_window_split_no_room()
+  " N horizontal windows need >= 2*N + 1 lines:
+  " - 1 line + 1 status line in each window
+  " - 1 Ex command line
+  "
+  " 2*N + 1 <= &lines
+  " N <= (lines - 1)/2
+  "
+  " Beyond that number of windows, E36: Not enough room is expected.
+  let hor_win_count = (&lines - 1)/2
+  let hor_split_count = hor_win_count - 1
+  for s in range(1, hor_split_count) | split | endfor
+  call assert_fails('split', 'E36:')
+
+  " N vertical windows need >= 2*(N - 1) + 1 columns:
+  " - 1 column + 1 separator for each window (except last window)
+  " - 1 column for the last window which does not have separator
+  "
+  " 2*(N - 1) + 1 <= &columns
+  " 2*N - 1 <= &columns
+  " N <= (&columns + 1)/2
+  let ver_win_count = (&columns + 1)/2
+  let ver_split_count = ver_win_count - 1
+  for s in range(1, ver_split_count) | vsplit | endfor
+  call assert_fails('vsplit', 'E36:')
+
+  %bw!
+endfunc
+
 func Test_window_preview()
   CheckFeature quickfix
 
diff --git a/src/version.c b/src/version.c
index fbd039b..8ef76da 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    426,
+/**/
     425,
 /**/
     424,