patch 8.2.0127: some buffer commands work in a popup window

Problem:    Some buffer commands work in a popup window.
Solution:   Disallow :bnext, :bprev, etc. (Naruhiko Nishino, closes #5494)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 78aee97..51d85c3 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -4613,6 +4613,9 @@
     static void
 ex_bnext(exarg_T *eap)
 {
+    if (ERROR_IF_POPUP_WINDOW)
+	return;
+
     goto_buffer(eap, DOBUF_CURRENT, FORWARD, (int)eap->line2);
     if (eap->do_ecmd_cmd != NULL)
 	do_cmdline_cmd(eap->do_ecmd_cmd);
@@ -4627,6 +4630,9 @@
     static void
 ex_bprevious(exarg_T *eap)
 {
+    if (ERROR_IF_POPUP_WINDOW)
+	return;
+
     goto_buffer(eap, DOBUF_CURRENT, BACKWARD, (int)eap->line2);
     if (eap->do_ecmd_cmd != NULL)
 	do_cmdline_cmd(eap->do_ecmd_cmd);
@@ -4641,6 +4647,9 @@
     static void
 ex_brewind(exarg_T *eap)
 {
+    if (ERROR_IF_POPUP_WINDOW)
+	return;
+
     goto_buffer(eap, DOBUF_FIRST, FORWARD, 0);
     if (eap->do_ecmd_cmd != NULL)
 	do_cmdline_cmd(eap->do_ecmd_cmd);
@@ -4653,6 +4662,9 @@
     static void
 ex_blast(exarg_T *eap)
 {
+    if (ERROR_IF_POPUP_WINDOW)
+	return;
+
     goto_buffer(eap, DOBUF_LAST, BACKWARD, 0);
     if (eap->do_ecmd_cmd != NULL)
 	do_cmdline_cmd(eap->do_ecmd_cmd);
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index 9370a11..654501b 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -913,6 +913,10 @@
   call assert_fails('call win_execute(winid, "next")', 'E994:')
   call assert_fails('call win_execute(winid, "rewind")', 'E994:')
   call assert_fails('call win_execute(winid, "buf")', 'E994:')
+  call assert_fails('call win_execute(winid, "bnext")', 'E994:')
+  call assert_fails('call win_execute(winid, "bprev")', 'E994:')
+  call assert_fails('call win_execute(winid, "bfirst")', 'E994:')
+  call assert_fails('call win_execute(winid, "blast")', 'E994:')
   call assert_fails('call win_execute(winid, "edit")', 'E994:')
   call assert_fails('call win_execute(winid, "enew")', 'E994:')
   call assert_fails('call win_execute(winid, "wincmd x")', 'E994:')
diff --git a/src/version.c b/src/version.c
index 71aecc8..d6fa59c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -743,6 +743,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    127,
+/**/
     126,
 /**/
     125,