vim-patch:7.4.1735

Problem:    It is not possible to only see part of the message history.  It is
            not possible to clear messages.
Solution:   Add a count to ":messages" and a clear argument. (Yasuhiro
            Matsumoto)

451f849fd6

runtime/doc/message.txt

@@ -19,6 +19,15 @@ The ":messages" command can be used to view previously given messages.  This
 is especially useful when messages have been overwritten or truncated.  This
 depends on the 'shortmess' option.
 
+	:messages		Show all messages.
+
+	:{count}messages	Show the {count} most recent messages.
+
+	:messages clear		Clear all messages.
+
+	:{count}messages clear	Clear messages, keeping only the {count} most
+				recent ones.
+
 The number of remembered messages is fixed at 20 for the tiny version and 200
 for other versions.
 
@@ -58,9 +67,9 @@ If you are lazy, it also works without the shift key: >
 When an error message is displayed, but it is removed before you could read
 it, you can see it again with: >
   :echo errmsg
-or view a list of recent messages with: >
+Or view a list of recent messages with: >
   :messages
-
+See `:messages` above.
 
 LIST OF MESSAGES
 			*E222* *E228* *E232* *E256* *E293* *E298* *E304* *E317*

src/nvim/ex_cmds.lua

@@ -1604,7 +1604,7 @@ return {
   },
   {
     command='messages',
-    flags=bit.bor(TRLBAR, CMDWIN),
+    flags=bit.bor(EXTRA, TRLBAR, RANGE, CMDWIN),
     addr_type=ADDR_LINES,
     func='ex_messages',
   },

src/nvim/message.c

@@ -720,14 +720,47 @@ int delete_first_msg(void)
 void ex_messages(exarg_T *eap)
 {
   struct msg_hist *p;
+  int c = 0;
 
-  msg_hist_off = TRUE;
+  if (STRCMP(eap->arg, "clear") == 0) {
+    int keep = eap->addr_count == 0 ? 0 : eap->line2;
 
-  for (p = first_msg_hist; p != NULL && !got_int; p = p->next)
-    if (p->msg != NULL)
+    while (msg_hist_len > keep) {
+      (void)delete_first_msg();
+    }
+    return;
+  }
+
+  if (*eap->arg != NUL) {
+    EMSG(_(e_invarg));
+    return;
+  }
+
+  msg_hist_off = true;
+
+  p = first_msg_hist;
+
+  if (eap->addr_count != 0) {
+    // Count total messages
+    for (; p != NULL && !got_int; p = p->next) {
+      c++;
+    }
+
+    c -= eap->line2;
+
+    // Skip without number of messages specified
+    for (p = first_msg_hist; p != NULL && !got_int && c > 0; p = p->next, c--) {
+    }
+  }
+
+  // Display what was not skipped.
+  for (; p != NULL && !got_int; p = p->next) {
+    if (p->msg != NULL) {
       msg_attr(p->msg, p->attr);
+    }
+  }
 
-  msg_hist_off = FALSE;
+  msg_hist_off = false;
 }
 
 /*

src/nvim/testdir/test_alot.vim

@@ -9,6 +9,7 @@ source test_expr.vim
 source test_expr_utf8.vim
 source test_feedkeys.vim
 source test_menu.vim
+source test_messages.vim
 source test_options.vim
 source test_popup.vim
 source test_regexp_utf8.vim

src/nvim/testdir/test_messages.vim

@@ -0,0 +1,42 @@
+" Tests for :messages
+
+function Test_messages()
+  let oldmore = &more
+  try
+    set nomore
+
+    let arr = map(range(10), '"hello" . v:val')
+    for s in arr
+      echomsg s | redraw
+    endfor
+    let result = ''
+
+    redir => result
+    2messages | redraw
+    redir END
+
+    " get last two messages
+    let msg = split(result, "\n")[1:][-2:]
+    call assert_equal(["hello8", "hello9"], msg)
+
+    " clear messages without last one
+    1messages clear
+    redir => result
+    redraw | 1messages
+    redir END
+    " get last last message
+    let msg = split(result, "\n")[1:][-1:]
+    call assert_equal(['hello9'], msg)
+
+    " clear all messages
+    messages clear
+    redir => result
+    redraw | 1messages
+    redir END
+    " get last last message
+    let msg = split(result, "\n")[1:][-1:]
+    call assert_equal([], msg)
+  finally
+    let &more = oldmore
+  endtry
+endfunction

src/nvim/version.c

@@ -709,7 +709,7 @@ static int included_patches[] = {
   // 1738,
   // 1737 NA
   // 1736 NA
-  // 1735,
+  1735,
   1734,
   // 1733 NA
   1732,