patch 9.1.0646: Vim9: imported function may not be found

Problem:  Vim9: imported function may not be found
Solution: Try to find the function by name (Ernie Rael)

fixes: #15381
closes: #15382

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index c8baaf6..7ed9123 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -497,6 +497,56 @@
   v9.CheckSourceDefAndScriptFailure(['call("reverse", [2], [1])'], ['E1013: Argument 3: type mismatch, expected dict<any> but got list<number>', 'E1206: Dictionary required for argument 3'])
 enddef
 
+def Test_call_imports()
+  # Use call with an imported function
+  var lines =<< trim END
+    vim9script
+
+    export const foo = 'foo'
+
+    export def Imported()
+    enddef
+
+    var count: number
+    export def ImportedListArg(l: list<number>)
+      count += 1
+      l[0] += count
+    enddef
+  END
+  writefile(lines, 'Test_call_imports_importme', 'D')
+  lines =<< trim END
+    vim9script
+    import './Test_call_imports_importme' as i_imp
+
+    var l = [12]
+    call('i_imp.ImportedListArg', [l])
+    assert_equal(13, l[0])
+    const ImportedListArg = i_imp.ImportedListArg
+    call('ImportedListArg', [l])
+    assert_equal(15, l[0])
+    const Imported = i_imp.Imported
+    call("Imported", [])
+
+    assert_equal('foo', i_imp.foo)
+    const foo = i_imp.foo
+    assert_equal('foo', foo)
+  END
+  v9.CheckSourceScriptSuccess(lines)
+
+  # A few error cases
+  lines =<< trim END
+    vim9script
+    import './Test_call_imports_importme' as i_imp
+    const Imported = i_imp.Imported
+    const foo = i_imp.foo
+
+    assert_fails('call("i_imp.foo", [])', 'E117:') # foo is not a function
+    assert_fails('call("foo", [])', 'E117:') # foo is not a function
+    assert_fails('call("i_xxx.foo", [])', 'E117:') # i_xxx not imported file
+  END
+  v9.CheckSourceScriptSuccess(lines)
+enddef
+
 def Test_ch_canread()
   if !has('channel')
     CheckFeature channel