Expand @{list} used as embedded arg if kw accepts varargs.

Fixes #4364.

atest/robot/keywords/embedded_arguments_library_keywords.robot

@@ -116,7 +116,13 @@ Embedded argument count must match accepted arguments
 Optional Non-Embedded Args Are Okay
     Check Test Case    ${TESTNAME}
 
-Star Args With Embedded Args Are Okay
+Varargs With Embedded Args Are Okay
+    Check Test Case    ${TESTNAME}
+
+List variable is expanded when keyword accepts varargs
+    Check Test Case    ${TESTNAME}
+
+Scalar variable containing list is not expanded when keyword accepts varargs
     Check Test Case    ${TESTNAME}
 
 Same name with different regexp works

atest/testdata/keywords/embedded_arguments_library_keywords.robot

@@ -7,6 +7,7 @@ ${INDENT}         ${SPACE * 4}
 ${foo}            foo
 ${bar}            bar
 ${zap}            zap
+@{list}           first    ${2}    third
 
 *** Test Cases ***
 Embedded Arguments In Library Keyword Name
@@ -146,10 +147,17 @@ Embedded argument count must match accepted arguments
 Optional Non-Embedded Args Are Okay
     Optional Non-Embedded Args Are Okay
 
-Star Args With Embedded Args Are Okay
-    @{ret} =    Star Args With Embedded Args are Okay
-    @{args} =    Create List    Embedded    Okay
-    Should Be Equal    ${ret}    ${args}
+Varargs With Embedded Args Are Okay
+    @{ret} =    Varargs With Embedded Args are Okay
+    Should Be Equal    ${ret}    ${{['Embedded', 'Okay']}}
+
+List variable is expanded when keyword accepts varargs
+    @{ret} =    Varargs With @{list} Args are Okay
+    Should Be Equal    ${ret}    ${{['first', 2, 'third', 'Okay']}}
+
+Scalar variable containing list is not expanded when keyword accepts varargs
+    @{ret} =    Varargs With ${list} Args are Okay
+    Should Be Equal    ${ret}    ${{[['first', 2, 'third'], 'Okay']}}
 
 Same name with different regexp works
     It is a car

atest/testdata/keywords/resources/embedded_args_in_lk_1.py

@@ -129,8 +129,8 @@ def optional_args_are_okay(nonembedded=1, okay=2, indeed=3):
     pass
 
 
-@keyword(name="Star Args With ${embedded} Args Are ${okay}")
-def star_args_are_okay(*args):
+@keyword(name="Varargs With ${embedded} Args Are ${okay}")
+def varargs_are_okay(*args):
     return args
 
 

src/robot/running/arguments/argumentresolver.py

@@ -32,8 +32,7 @@ def __init__(self, argspec, resolve_named=True,
 
     def resolve(self, arguments, variables=None):
         positional, named = self._named_resolver.resolve(arguments, variables)
-        positional, named = self._variable_replacer.replace(positional, named,
-                                                            variables)
+        positional, named = self._variable_replacer.replace(positional, named, variables)
         positional, named = self._dict_to_kwargs.handle(positional, named)
         self._argument_validator.validate(positional, named,
                                           dryrun=variables is None)

src/robot/running/handlers.py

@@ -307,10 +307,13 @@ def create_runner(self, name):
         return EmbeddedArgumentsRunner(self, name)
 
     def resolve_arguments(self, args, variables=None):
+        argspec = self._orig_handler.arguments
         if variables:
-            args = [variables.replace_scalar(a) for a in args]
+            if argspec.var_positional:
+                args = variables.replace_list(args)
+            else:
+                args = [variables.replace_scalar(a) for a in args]
             self.embedded.validate(args)
-        argspec = self._orig_handler.arguments
         return argspec.convert(args, named={}, converters=self.library.converters,
                                dry_run=not variables)