patch 8.2.4260: Vim9: can still use a global function without g:

Problem:    Vim9: can still use a global function without g: at the script
            level.
Solution:   Also check for g: at the script level. (issue #9637)
diff --git a/src/testdir/dumps/Test_popupwin_scroll_11.dump b/src/testdir/dumps/Test_popupwin_scroll_11.dump
index 938f86a..96b3d27 100644
--- a/src/testdir/dumps/Test_popupwin_scroll_11.dump
+++ b/src/testdir/dumps/Test_popupwin_scroll_11.dump
@@ -7,4 +7,4 @@
 |7| @20|4+0#0000001#ffd7ff255| @28| +0#0000000#a8a8a8255| +0&#ffffff0@21
 |8| @73
 |9| @73
-|:|c|a|l@1| |P|o|p|u|p|S|c|r|o|l@1|(|)| @37|1|,|1| @10|T|o|p| 
+|:|c|a|l@1| |g|:|P|o|p|u|p|S|c|r|o|l@1|(|)| @35|1|,|1| @10|T|o|p| 
diff --git a/src/testdir/dumps/Test_popupwin_scroll_12.dump b/src/testdir/dumps/Test_popupwin_scroll_12.dump
index 9fa71c7..e54a187 100644
--- a/src/testdir/dumps/Test_popupwin_scroll_12.dump
+++ b/src/testdir/dumps/Test_popupwin_scroll_12.dump
@@ -7,4 +7,4 @@
 |7| @20|l+0#0000001#ffd7ff255|o|n|g| |l|i|n|e| |l|o|n|g| |l|i|n|e| |l|o|n|g| |l|i|n|e| | +0#0000000#a8a8a8255| +0&#ffffff0@21
 |8| @73
 |9| @73
-|:|c|a|l@1| |P|o|p|u|p|S|c|r|o|l@1|(|)| @37|1|,|1| @10|T|o|p| 
+|:|c|a|l@1| |g|:|P|o|p|u|p|S|c|r|o|l@1|(|)| @35|1|,|1| @10|T|o|p| 
diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index 5cfa462..35cacf2 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -1422,7 +1422,7 @@
     call assert_fails("set completefunc=funcref('abc')", "E700:")
 
     #" set 'completefunc' to a non-existing function
-    set completefunc=CompleteFunc2
+    set completefunc=g:CompleteFunc2
     call setline(1, 'five')
     call assert_fails("set completefunc=function('NonExistingFunc')", 'E700:')
     call assert_fails("LET &completefunc = function('NonExistingFunc')", 'E700:')
@@ -1679,7 +1679,7 @@
     call assert_fails("set omnifunc=funcref('abc')", "E700:")
 
     #" set 'omnifunc' to a non-existing function
-    set omnifunc=OmniFunc2
+    set omnifunc=g:OmniFunc2
     call setline(1, 'nine')
     call assert_fails("set omnifunc=function('NonExistingFunc')", 'E700:')
     call assert_fails("LET &omnifunc = function('NonExistingFunc')", 'E700:')
@@ -1936,7 +1936,7 @@
     call assert_fails("set thesaurusfunc=funcref('abc')", "E700:")
 
     #" set 'thesaurusfunc' to a non-existing function
-    set thesaurusfunc=TsrFunc2
+    set thesaurusfunc=g:TsrFunc2
     call setline(1, 'ten')
     call assert_fails("set thesaurusfunc=function('NonExistingFunc')", 'E700:')
     call assert_fails("LET &thesaurusfunc = function('NonExistingFunc')", 'E700:')
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index 5a088b4..fda6992 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -2263,7 +2263,7 @@
 	    \ wrap: true,
 	    \ scrollbar: true,
 	    \ mapping: false,
-	    \ filter: Popup_filter,
+	    \ filter: g:Popup_filter,
 	    \ })
     enddef
 
@@ -2328,7 +2328,7 @@
   call VerifyScreenDump(buf, 'Test_popupwin_scroll_10', {})
 
   " check size with non-wrapping lines
-  call term_sendkeys(buf, ":call PopupScroll()\<CR>")
+  call term_sendkeys(buf, ":call g:PopupScroll()\<CR>")
   call VerifyScreenDump(buf, 'Test_popupwin_scroll_11', {})
 
   " check size with wrapping lines
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index 7eb7eae..e3606d8 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -75,7 +75,7 @@
 
   # lower case name is OK for a list
   var lambdaLines =<< trim END
-      var lambdaList: list<func> = [Test_syntax]
+      var lambdaList: list<func> = [g:Test_syntax]
       lambdaList[0] = () => "lambda"
   END
   v9.CheckDefAndScriptSuccess(lambdaLines)
@@ -890,7 +890,7 @@
 
 def Test_assignment_partial()
   var lines =<< trim END
-      var Partial: func(): string = function(PartFuncBool, [true])
+      var Partial: func(): string = function(g:PartFuncBool, [true])
       assert_equal('done', Partial())
   END
   v9.CheckDefAndScriptSuccess(lines)
@@ -1393,7 +1393,7 @@
   v9.CheckDefFailure(['var name: dict <number>'], 'E1068:')
   v9.CheckDefFailure(['var name: dict<number'], 'E1009:')
 
-  assert_fails('s/^/\=Mess()/n', 'E794:')
+  assert_fails('s/^/\=g:Mess()/n', 'E794:')
   v9.CheckDefFailure(['var name: dict<number'], 'E1009:')
 
   v9.CheckDefFailure(['w:foo: number = 10'],
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 16be67c..d6b42bb 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -1303,7 +1303,7 @@
 enddef
 
 def Test_filter_wrong_dict_key_type()
-  assert_fails('Wrong_dict_key_type([1, v:null, 3])', 'E1013:')
+  assert_fails('g:Wrong_dict_key_type([1, v:null, 3])', 'E1013:')
 enddef
 
 def Test_filter_return_type()
diff --git a/src/testdir/test_vim9_cmd.vim b/src/testdir/test_vim9_cmd.vim
index 92c86d8..3d9edee 100644
--- a/src/testdir/test_vim9_cmd.vim
+++ b/src/testdir/test_vim9_cmd.vim
@@ -1324,7 +1324,7 @@
   bwipe!
 enddef
 
-def g:SomeComplFunc(findstart: number, base: string): any
+def s:SomeComplFunc(findstart: number, base: string): any
   if findstart
     return 0
   else
diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index 5fbdef8..41aaa28 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -887,7 +887,7 @@
 enddef
 
 
-def HasEval()
+def s:HasEval()
   if has("eval")
     echo "yes"
   else
@@ -895,7 +895,7 @@
   endif
 enddef
 
-def HasNothing()
+def s:HasNothing()
   if has("nothing")
     echo "yes"
   else
@@ -903,7 +903,7 @@
   endif
 enddef
 
-def HasSomething()
+def s:HasSomething()
   if has("nothing")
     echo "nothing"
   elseif has("something")
@@ -915,7 +915,7 @@
   endif
 enddef
 
-def HasGuiRunning()
+def s:HasGuiRunning()
   if has("gui_running")
     echo "yes"
   else
@@ -2487,7 +2487,7 @@
         res)
 enddef
 
-func Legacy() dict
+func s:Legacy() dict
   echo 'legacy'
 endfunc
 
@@ -2501,7 +2501,7 @@
   assert_match('<SNR>\d*_UseMember\_s*' ..
           'var d = {func: Legacy}\_s*' ..
           '\d PUSHS "func"\_s*' ..
-          '\d PUSHFUNC "g:Legacy"\_s*' ..
+          '\d PUSHFUNC "<80><fd>R\d\+_Legacy"\_s*' ..
           '\d NEWDICT size 1\_s*' ..
           '\d STORE $0\_s*' ..
 
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index d2f69ab..bf5a0d0 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -61,12 +61,17 @@
       var RetThat: func = g:atrue ? RetOne : RetTwo
       assert_equal(function('len'), RetThat)
 
-      var X = FuncOne
-      var Y = FuncTwo
-      var Z = g:cond ? FuncOne : FuncTwo
+      var X = g:FuncOne
+      var Y = g:FuncTwo
+      var Z = g:cond ? g:FuncOne : g:FuncTwo
       assert_equal(123, Z(3))
   END
   v9.CheckDefAndScriptSuccess(lines)
+
+  lines =<< trim END
+      var Z = g:cond ? FuncOne : FuncTwo
+  END
+  v9.CheckDefAndScriptFailure(lines, ['E1001: Variable not found: FuncOne', 'E121: Undefined variable: FuncTwo'])
 enddef
 
 def Test_expr1_trinary_vimscript()
@@ -209,9 +214,9 @@
 
   " missing argument detected even when common type is used
   call v9.CheckDefAndScriptFailure([
-	\ 'var X = FuncOne',
-	\ 'var Y = FuncTwo',
-	\ 'var Z = g:cond ? FuncOne : FuncTwo',
+	\ 'var X = g:FuncOne',
+	\ 'var Y = g:FuncTwo',
+	\ 'var Z = g:cond ? g:FuncOne : g:FuncTwo',
 	\ 'Z()'], 'E119:', 4)
 endfunc
 
@@ -2334,7 +2339,7 @@
       def Test()
         var Ref = g:GlobalFunc
         assert_equal('global', Ref())
-        Ref = GlobalFunc
+        Ref = g:GlobalFunc
         assert_equal('global', Ref())
 
         Ref = s:ScriptFunc
@@ -3083,12 +3088,12 @@
   v9.CheckDefAndScriptFailure(["var Ref = function('len' [1, 2])"], ['E1123:', 'E116:'], 1)
 enddef
 
-def g:ExistingGloba(): string
+def g:ExistingGlobal(): string
   return 'existing'
 enddef
 
 def Test_expr8_call_global()
-  assert_equal('existing', g:ExistingGloba())
+  assert_equal('existing', g:ExistingGlobal())
 
   def g:DefinedLater(): string
     return 'later'
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 9378c14..41ba2da 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -340,7 +340,7 @@
 def Test_return_something()
   g:ReturnString()->assert_equal('string')
   g:ReturnNumber()->assert_equal(123)
-  assert_fails('ReturnGlobal()', 'E1012: Type mismatch; expected number but got string', '', 1, 'ReturnGlobal')
+  assert_fails('g:ReturnGlobal()', 'E1012: Type mismatch; expected number but got string', '', 1, 'ReturnGlobal')
 
   var lines =<< trim END
       vim9script
@@ -943,7 +943,7 @@
       def g:Func(): string
         return 'global'
       enddef
-      assert_equal('global', Func())
+      assert_equal('global', g:Func())
       delfunc g:Func
   END
   v9.CheckScriptSuccess(lines)
@@ -1498,14 +1498,14 @@
 
 def Test_func_type_varargs()
   var RefDefArg: func(?string)
-  RefDefArg = FuncOneDefArg
+  RefDefArg = g:FuncOneDefArg
   RefDefArg()
   s:value->assert_equal('text')
   RefDefArg('some')
   s:value->assert_equal('some')
 
   var RefDef2Arg: func(?number, ?string): string
-  RefDef2Arg = FuncTwoDefArg
+  RefDef2Arg = g:FuncTwoDefArg
   RefDef2Arg()->assert_equal('123text')
   RefDef2Arg(99)->assert_equal('99text')
   RefDef2Arg(77, 'some')->assert_equal('77some')
@@ -1514,7 +1514,7 @@
   v9.CheckDefFailure(['var RefWrong: func(?string, string)'], 'E1007:')
 
   var RefVarargs: func(...list<string>): string
-  RefVarargs = FuncVarargs
+  RefVarargs = g:FuncVarargs
   RefVarargs()->assert_equal('')
   RefVarargs('one')->assert_equal('one')
   RefVarargs('one', 'two')->assert_equal('one,two')
@@ -1721,7 +1721,7 @@
 
 def Test_error_in_nested_function()
   # Error in called function requires unwinding the call stack.
-  assert_fails('FuncWithForwardCall()', 'E1096:', '', 1, 'FuncWithForwardCall')
+  assert_fails('g:FuncWithForwardCall()', 'E1096:', '', 1, 'FuncWithForwardCall')
 enddef
 
 def Test_nested_function_with_nextcmd()
@@ -2199,7 +2199,7 @@
   s:funcResult->assert_equal(22)
 
   s:funcResult = 0
-  Ref2 = FuncOneArgRetNumber
+  Ref2 = g:FuncOneArgRetNumber
   Ref2(13)->assert_equal(13)
   s:funcResult->assert_equal(13)
 enddef
@@ -2232,11 +2232,11 @@
   RefVoid = g:FuncNoArgNoRet
   RefVoid = g:FuncOneArgNoRet
   v9.CheckDefFailure(['var RefVoid: func: void', 'RefVoid = g:FuncNoArgRetNumber'], 'E1012: Type mismatch; expected func(...) but got func(): number')
-  v9.CheckDefFailure(['var RefVoid: func: void', 'RefVoid = FuncNoArgRetString'], 'E1012: Type mismatch; expected func(...) but got func(): string')
+  v9.CheckDefFailure(['var RefVoid: func: void', 'RefVoid = g:FuncNoArgRetString'], 'E1012: Type mismatch; expected func(...) but got func(): string')
 
   var RefAny: func(): any
   RefAny = g:FuncNoArgRetNumber
-  RefAny = FuncNoArgRetString
+  RefAny = g:FuncNoArgRetString
   v9.CheckDefFailure(['var RefAny: func(): any', 'RefAny = g:FuncNoArgNoRet'], 'E1012: Type mismatch; expected func(): any but got func()')
   v9.CheckDefFailure(['var RefAny: func(): any', 'RefAny = g:FuncOneArgNoRet'], 'E1012: Type mismatch; expected func(): any but got func(number)')
 
@@ -2244,12 +2244,12 @@
 
   var RefNr: func: number
   RefNr = g:FuncNoArgRetNumber
-  RefNr = FuncOneArgRetNumber
+  RefNr = g:FuncOneArgRetNumber
   v9.CheckDefFailure(['var RefNr: func: number', 'RefNr = g:FuncNoArgNoRet'], 'E1012: Type mismatch; expected func(...): number but got func()')
-  v9.CheckDefFailure(['var RefNr: func: number', 'RefNr = FuncNoArgRetString'], 'E1012: Type mismatch; expected func(...): number but got func(): string')
+  v9.CheckDefFailure(['var RefNr: func: number', 'RefNr = g:FuncNoArgRetString'], 'E1012: Type mismatch; expected func(...): number but got func(): string')
 
   var RefStr: func: string
-  RefStr = FuncNoArgRetString
+  RefStr = g:FuncNoArgRetString
   RefStr = FuncOneArgRetString
   v9.CheckDefFailure(['var RefStr: func: string', 'RefStr = g:FuncNoArgNoRet'], 'E1012: Type mismatch; expected func(...): string but got func()')
   v9.CheckDefFailure(['var RefStr: func: string', 'RefStr = g:FuncNoArgRetNumber'], 'E1012: Type mismatch; expected func(...): string but got func(): number')
@@ -2260,7 +2260,7 @@
 
   v9.CheckDefFailure(['var Ref1: func()', 'Ref1 = g:FuncNoArgRetNumber'], 'E1012: Type mismatch; expected func() but got func(): number')
   v9.CheckDefFailure(['var Ref1: func()', 'Ref1 = g:FuncOneArgNoRet'], 'E1012: Type mismatch; expected func() but got func(number)')
-  v9.CheckDefFailure(['var Ref1: func()', 'Ref1 = FuncOneArgRetNumber'], 'E1012: Type mismatch; expected func() but got func(number): number')
+  v9.CheckDefFailure(['var Ref1: func()', 'Ref1 = g:FuncOneArgRetNumber'], 'E1012: Type mismatch; expected func() but got func(number): number')
   v9.CheckDefFailure(['var Ref1: func(bool)', 'Ref1 = g:FuncTwoArgNoRet'], 'E1012: Type mismatch; expected func(bool) but got func(bool, number)')
   v9.CheckDefFailure(['var Ref1: func(?bool)', 'Ref1 = g:FuncTwoArgNoRet'], 'E1012: Type mismatch; expected func(?bool) but got func(bool, number)')
   v9.CheckDefFailure(['var Ref1: func(...bool)', 'Ref1 = g:FuncTwoArgNoRet'], 'E1012: Type mismatch; expected func(...bool) but got func(bool, number)')
@@ -3355,7 +3355,7 @@
 enddef
 
 def Test_opfunc()
-  nnoremap <F3> <cmd>set opfunc=Opfunc<cr>g@
+  nnoremap <F3> <cmd>set opfunc=g:Opfunc<cr>g@
   def g:Opfunc(_: any): string
     setline(1, 'ASDF')
     return ''
diff --git a/src/testdir/test_vim9_import.vim b/src/testdir/test_vim9_import.vim
index 440bef1..7d474e1 100644
--- a/src/testdir/test_vim9_import.vim
+++ b/src/testdir/test_vim9_import.vim
@@ -2018,7 +2018,7 @@
   delete('Xdir', 'rf')
 enddef
 
-def Test_autoload_name_wring()
+def Test_autoload_name_wrong()
   var lines =<< trim END
      vim9script
      def Xscriptname#Func()