vim-patch:8.1.0495: :filter only supports some commands

Problem:    :filter only supports some commands.
Solution:   Add :filter support for more commands. (Marcin Szamotulski,
            closes vim/vim#2856)
f86db78fed

runtime/doc/various.txt

@@ -358,7 +358,18 @@ g8			Print the hex values of the bytes used in the
 			The pattern is matched against the relevant part of
 			the output, not necessarily the whole line. Only some
 			commands support filtering, try it out to check if it
-			works.
+			works. Some of the commands that support filtering:
+                          |:#|          - filter whole line
+                          |:command|    - filter by command name
+                          |:files|      - filter by file name
+                          |:highlight|  - filter by highlight group
+                          |:jumps|      - filter by file name
+                          |:let|        - filter by variable name
+                          |:list|       - filter whole line
+                          |:llist|      - filter by file name or module name
+                          |:oldfiles|   - filter by file name
+                          |:clist|      - filter by file name or module name
+                          |:set|        - filter by variable name
 
 			Only normal messages are filtered, error messages are
 			not.

src/nvim/eval.c

@@ -1782,6 +1782,15 @@ static void list_hashtable_vars(hashtab_T *ht, const char *prefix, int empty,
     if (!HASHITEM_EMPTY(hi)) {
       todo--;
       di = TV_DICT_HI2DI(hi);
+      char buf[IOSIZE];
+
+      // apply :filter /pat/ to variable name
+      xstrlcpy(buf, prefix, IOSIZE - 1);
+      xstrlcat(buf, (char *)di->di_key, IOSIZE);
+      if (message_filtered((char_u *)buf)) {
+        continue;
+      }
+
       if (empty || di->di_tv.v_type != VAR_STRING
           || di->di_tv.vval.v_string != NULL) {
         list_one_var(di, prefix, first);
@@ -20851,6 +20860,9 @@ void ex_function(exarg_T *eap)
         if (!HASHITEM_EMPTY(hi)) {
           --todo;
           fp = HI2UF(hi);
+          if (message_filtered(fp->uf_name)) {
+            continue;
+          }
           if (!func_name_refcount(fp->uf_name)) {
             list_func_head(fp, false);
           }

src/nvim/mark.c

@@ -786,8 +786,11 @@ void ex_jumps(exarg_T *eap)
   for (i = 0; i < curwin->w_jumplistlen && !got_int; ++i) {
     if (curwin->w_jumplist[i].fmark.mark.lnum != 0) {
       name = fm_getname(&curwin->w_jumplist[i].fmark, 16);
-      if (name == NULL)             /* file name not available */
+
+      // apply :filter /pat/ or file name not available
+      if (name == NULL || message_filtered(name)) {
         continue;
+      }
 
       msg_putchar('\n');
       if (got_int) {

src/nvim/option.c

@@ -5047,6 +5047,11 @@ showoptions(
     // collect the items in items[]
     item_count = 0;
     for (p = &options[0]; p->fullname != NULL; p++) {
+      // apply :filter /pat/
+      if (message_filtered((char_u *)p->fullname)) {
+        continue;
+      }
+
       varp = NULL;
       if (opt_flags != 0) {
         if (p->indir != PV_NONE) {

src/nvim/syntax.c

@@ -350,7 +350,7 @@ static reg_extmatch_T *next_match_extmatch = NULL;
 
 /*
  * A state stack is an array of integers or stateitem_T, stored in a
- * garray_T.  A state stack is invalid if it's itemsize entry is zero.
+ * garray_T.  A state stack is invalid if its itemsize entry is zero.
  */
 #define INVALID_STATE(ssp)  ((ssp)->ga_itemsize == 0)
 #define VALID_STATE(ssp)    ((ssp)->ga_itemsize != 0)
@@ -7028,6 +7028,10 @@ static void highlight_list_one(const int id)
   struct hl_group *const sgp = &HL_TABLE()[id - 1];  // index is ID minus one
   bool didh = false;
 
+  if (message_filtered(sgp->sg_name)) {
+    return;
+  }
+
   didh = highlight_list_arg(id, didh, LIST_ATTR,
       sgp->sg_cterm, NULL, "cterm");
   didh = highlight_list_arg(id, didh, LIST_INT,

src/nvim/testdir/test_filter_cmd.vim

@@ -87,3 +87,43 @@ func Test_filter_cmd_with_filter()
   call assert_equal('a|b', out)
   set shelltemp&
 endfunction
+
+func Test_filter_commands()
+  let g:test_filter_a = 1
+  let b:test_filter_b = 2
+  let test_filter_c = 3
+
+  " Test filtering :let command
+  let res = split(execute("filter /^test_filter/ let"), "\n")
+  call assert_equal(["test_filter_a         #1"], res)
+
+  let res = split(execute("filter /\\v^(b:)?test_filter/ let"), "\n")
+  call assert_equal(["test_filter_a         #1", "b:test_filter_b       #2"], res)
+
+  unlet g:test_filter_a
+  unlet b:test_filter_b
+  unlet test_filter_c
+
+  " Test filtering :set command
+  let res = join(split(execute("filter /^help/ set"), "\n")[1:], " ")
+  call assert_match('^\s*helplang=\w*$', res)
+
+  " Test filtering :llist command
+  call setloclist(0, [{"filename": "/path/vim.c"}, {"filename": "/path/vim.h"}, {"module": "Main.Test"}])
+  let res = split(execute("filter /\\.c$/ llist"), "\n")
+  call assert_equal([" 1 /path/vim.c:  "], res)
+
+  let res = split(execute("filter /\\.Test$/ llist"), "\n")
+  call assert_equal([" 3 Main.Test:  "], res)
+
+  " Test filtering :jump command
+  e file.c
+  e file.h
+  e file.hs
+  let res = split(execute("filter /\.c$/ jumps"), "\n")[1:]
+  call assert_equal(["   2     1    0 file.c", ">"], res)
+
+  bwipe file.c
+  bwipe file.h
+  bwipe file.hs
+endfunc