count -h should report 1

The count command should not treat any flag specially. Not even `-h` and
`--help`. It should simply return a count of the number of arguments it
received.

Fixes #4189

CHANGELOG.md

@@ -19,6 +19,7 @@
 - `help` can now open the tutorial.
 - `echo -h` now correctly echoes `-h` (#4120).
 - Stop converting empty elements in MANPATH to "." (#4158). The behavior being changed was introduced in fish 2.6.0.
+- `count -h` and `count --help` now return one (#4189).
 - Added completions for:
  - `as` (#4130).
  - `jest` (#4142).

src/builtin.cpp

@@ -491,7 +491,7 @@ bool builtin_exists(const wcstring &cmd) { return static_cast<bool>(builtin_look
 
 /// Is the command a keyword or a builtin we need to special-case the handling of `-h` and `--help`.
 static const wcstring_list_t help_builtins({L"for", L"while", L"function", L"if", L"end", L"switch",
-                                            L"case", L"count", L"printf"});
+                                            L"case", L"printf"});
 static bool cmd_needs_help(const wchar_t *cmd) { return contains(help_builtins, cmd); }
 
 /// Execute a builtin command

tests/count.in

@@ -0,0 +1,17 @@
+# Validate the behavior of the `count` command.
+
+echo '# no args'
+count
+
+echo '# one args'
+count x
+
+echo '# two args'
+count x y
+
+echo '# args that look like flags or are otherwise special'
+count -h
+count --help
+count --
+count -- abc
+count def -- abc

tests/count.out

@@ -0,0 +1,12 @@
+# no args
+0
+# one args
+1
+# two args
+2
+# args that look like flags or are otherwise special
+1
+1
+1
+2
+3