fix(api): make nvim_parse_cmd work correctly with both range and count

It seems range and count can be used together in commands. This PR fixes
the behavior of `nvim_parse_cmd` for those cases by removing the mutual
exclusivity of "range" and "count". It also removes range line number
validation for `nvim_parse_cmd` as it's not its job to validate the
command.

runtime/doc/api.txt

@@ -1782,8 +1782,7 @@ nvim_parse_cmd({str}, {opts})                               *nvim_parse_cmd()*
                       item was specified and two elements if both range items
                       were specified.
                     • count: (number) Any |<count>| that was supplied to the
-                      command. -1 if command cannot take a count. Mutually
-                      exclusive with "range".
+                      command. -1 if command cannot take a count.
                     • reg: (number) The optional command |<register>|, if
                       specified. Empty string if not specified or if command
                       cannot take a register.

src/nvim/api/vimscript.c

@@ -752,7 +752,7 @@ Dictionary nvim_parse_expression(String expr, String flags, Boolean highlight, E
 ///                          no range was specified, one element if only a single range item was
 ///                          specified and two elements if both range items were specified.
 ///         - count: (number) Any |<count>| that was supplied to the command. -1 if command cannot
-///                           take a count. Mutually exclusive with "range".
+///                           take a count.
 ///         - reg: (number) The optional command |<register>|, if specified. Empty string if not
 ///                         specified or if command cannot take a register.
 ///         - bang: (boolean) Whether command contains a |<bang>| (!) modifier.
@@ -853,7 +853,7 @@ Dictionary nvim_parse_cmd(String str, Dictionary opts, Error *err)
     PUT(result, "cmd", CSTR_TO_OBJ((char *)get_command_name(NULL, ea.cmdidx)));
   }
 
-  if ((ea.argt & EX_RANGE) && !(ea.argt & EX_COUNT) && ea.addr_count > 0) {
+  if ((ea.argt & EX_RANGE) && ea.addr_count > 0) {
     Array range = ARRAY_DICT_INIT;
     if (ea.addr_count > 1) {
       ADD(range, INTEGER_OBJ(ea.line1));

src/nvim/ex_docmd.c

@@ -1320,7 +1320,7 @@ static void parse_register(exarg_T *eap)
   }
 }
 
-static int parse_count(exarg_T *eap, char **errormsg)
+static int parse_count(exarg_T *eap, char **errormsg, bool validate)
 {
   // Check for a count.  When accepting a EX_BUFNAME, don't use "123foo" as a
   // count, it's a buffer name.
@@ -1348,7 +1348,7 @@ static int parse_count(exarg_T *eap, char **errormsg)
       eap->line2 += n - 1;
       eap->addr_count++;
       // Be vi compatible: no error message for out of range.
-      if (eap->line2 > curbuf->b_ml.ml_line_count) {
+      if (validate && eap->line2 > curbuf->b_ml.ml_line_count) {
         eap->line2 = curbuf->b_ml.ml_line_count;
       }
     }
@@ -1426,7 +1426,7 @@ bool parse_cmdline(char *cmdline, exarg_T *eap, CmdParseInfo *cmdinfo, char **er
   }
   p = find_command(eap, NULL);
 
-  // Set command attribute type and parse command range
+  // Set command address type and parse command range
   set_cmd_addr_type(eap, (char_u *)p);
   eap->cmd = cmd;
   if (parse_cmd_address(eap, errormsg, false) == FAIL) {
@@ -1499,7 +1499,7 @@ bool parse_cmdline(char *cmdline, exarg_T *eap, CmdParseInfo *cmdinfo, char **er
 
   // Parse register and count
   parse_register(eap);
-  if (parse_count(eap, errormsg) == FAIL) {
+  if (parse_count(eap, errormsg, false) == FAIL) {
     return false;
   }
 
@@ -1981,7 +1981,7 @@ static char *do_one_cmd(char **cmdlinep, int flags, cstack_T *cstack, LineGetter
 
   // Parse register and count
   parse_register(&ea);
-  if (parse_count(&ea, &errormsg) == FAIL) {
+  if (parse_count(&ea, &errormsg, true) == FAIL) {
     goto doend;
   }
 

test/functional/api/vim_spec.lua

@@ -3176,7 +3176,7 @@ describe('API', function()
         cmd = 'buffer',
         args = {},
         bang = false,
-        range = {},
+        range = { 1 },
         count = 1,
         reg = '',
         addr = 'buf',
@@ -3243,6 +3243,42 @@ describe('API', function()
         }
       }, meths.parse_cmd('put +', {}))
     end)
+    it('works with range, count and register', function()
+      eq({
+        cmd = 'delete',
+        args = {},
+        bang = false,
+        range = { 3, 7 },
+        count = 7,
+        reg = '*',
+        addr = 'line',
+        magic = {
+            file = false,
+            bar = true
+        },
+        nargs = '0',
+        nextcmd = '',
+        mods = {
+          browse = false,
+          confirm = false,
+          emsg_silent = false,
+          hide = false,
+          keepalt = false,
+          keepjumps = false,
+          keepmarks = false,
+          keeppatterns = false,
+          lockmarks = false,
+          noautocmd = false,
+          noswapfile = false,
+          sandbox = false,
+          silent = false,
+          vertical = false,
+          split = "",
+          tab = 0,
+          verbose = -1
+        }
+      }, meths.parse_cmd('1,3delete * 5', {}))
+    end)
     it('works with bang', function()
       eq({
         cmd = 'write',