vim-patch:7.4.2244

Problem:    Adding pattern to ":oldfiles" is not a generic solution.
Solution:   Add the ":filter /pat/ cmd" command modifier.  Only works for some
            commands right now.

7b668e83d0

src/nvim/message.c

@@ -31,6 +31,7 @@
 #include "nvim/ops.h"
 #include "nvim/option.h"
 #include "nvim/normal.h"
+#include "nvim/regexp.h"
 #include "nvim/screen.h"
 #include "nvim/strings.h"
 #include "nvim/ui.h"
@@ -148,6 +149,12 @@ msg_attr_keep (
   int retval;
   char_u *buf = NULL;
 
+  // Skip messages not match ":filter pattern".
+  // Don't filter when there is an error.
+  if (!emsg_on_display && message_filtered(s)) {
+    return true;
+  }
+
   if (attr == 0) {
     set_vim_var_string(VV_STATUSMSG, (char *) s, -1);
   }
@@ -1783,6 +1790,14 @@ static void msg_puts_display(const char_u *str, int maxlen, int attr,
   msg_check();
 }
 
+/// Return true when ":filter pattern" was used and "msg" does not match
+/// "pattern".
+bool message_filtered(char_u *msg)
+{
+  return cmdmod.filter_regmatch.regprog != NULL
+    && !vim_regexec(&cmdmod.filter_regmatch, msg, (colnr_T)0);
+}
+
 /*
  * Scroll the screen up one line for displaying the next message line.
  */