[ruby/prism] Reject p(p a, &block => value) and similar

They were being parsed as `p((p a, &block) => value)`.
When we get to this point, we must not just have parsed a command call, always consuming the `=>` is not correct.

Closes [Bug #21622]

ruby/prism@796ab0edf4

Author: Earlopain

prism/prism.c

@@ -14232,6 +14232,25 @@ parse_assocs(pm_parser_t *parser, pm_static_literals_t *literals, pm_node_t *nod
     return contains_keyword_splat;
 }
 
+static inline bool
+argument_allowed_for_bare_hash(pm_parser_t *parser, pm_node_t *argument) {
+    if (pm_symbol_node_label_p(argument)) {
+        return true;
+    }
+
+    switch (PM_NODE_TYPE(argument)) {
+        case PM_CALL_NODE: {
+            pm_call_node_t *cast = (pm_call_node_t *) argument;
+            if (cast->opening_loc.start == NULL && cast->arguments != NULL) {
+                return false;
+            }
+            break;
+        }
+        default: break;
+    }
+    return accept1(parser, PM_TOKEN_EQUAL_GREATER);
+}
+
 /**
  * Append an argument to a list of arguments.
  */
@@ -14389,7 +14408,7 @@ parse_arguments(pm_parser_t *parser, pm_arguments_t *arguments, bool accepts_for
                 bool contains_keywords = false;
                 bool contains_keyword_splat = false;
 
-                if (pm_symbol_node_label_p(argument) || accept1(parser, PM_TOKEN_EQUAL_GREATER)) {
+                if (argument_allowed_for_bare_hash(parser, argument)){
                     if (parsed_bare_hash) {
                         pm_parser_err_previous(parser, PM_ERR_ARGUMENT_BARE_HASH);
                     }

test/prism/errors/command_calls_35.txt

@@ -0,0 +1,41 @@
+p(p a, x: b => value)
+            ^~ unexpected '=>'; expected a `)` to close the arguments
+                    ^ unexpected ')', expecting end-of-input
+                    ^ unexpected ')', ignoring it
+
+p(p a, x: => value)
+          ^~ unexpected '=>'; expected a `)` to close the arguments
+                  ^ unexpected ')', expecting end-of-input
+                  ^ unexpected ')', ignoring it
+
+p(p a, &block => value)
+              ^~ unexpected '=>'; expected a `)` to close the arguments
+                      ^ unexpected ')', expecting end-of-input
+                      ^ unexpected ')', ignoring it
+
+p(p a, *args => value)
+             ^~ unexpected '=>'; expected a `)` to close the arguments
+                     ^ unexpected ')', expecting end-of-input
+                     ^ unexpected ')', ignoring it
+
+p(p a, **kwargs => value)
+                ^~ unexpected '=>'; expected a `)` to close the arguments
+                        ^ unexpected ')', expecting end-of-input
+                        ^ unexpected ')', ignoring it
+
+p p 1, &block => 2, &block
+              ^~ unexpected '=>', expecting end-of-input
+              ^~ unexpected '=>', ignoring it
+                  ^ unexpected ',', expecting end-of-input
+                  ^ unexpected ',', ignoring it
+                    ^ unexpected '&', ignoring it
+
+p p p 1 => 2 => 3 => 4
+             ^~ unexpected '=>', expecting end-of-input
+             ^~ unexpected '=>', ignoring it
+
+p[p a, x: b => value]
+           ^ expected a matching `]`
+                    ^ unexpected ']', expecting end-of-input
+                    ^ unexpected ']', ignoring it
+

test/prism/fixtures/command_method_call.txt

@@ -39,3 +39,9 @@ def foo = bar 1
 !foo 1 or !bar 2
 
 not !foo 1
+
+foo(bar baz, key => value)
+
+foo(bar baz, KEY => value)
+
+foo(bar baz, :key => value)