patch 8.2.2264: Vim9: no error for mismatched :endfunc or :enddef

Problem:    Vim9: no error for mismatched :endfunc or :enddef.
Solution:   Check for the mismatch. (issue #7582)

src/errors.h

@@ -335,3 +335,7 @@ EXTERN char e_script_variable_invalid_after_reload_in_function_str[]
 	INIT(= N_("E1149: Script variable is invalid after reload in function %s"));
 EXTERN char e_script_variable_type_changed[]
 	INIT(= N_("E1150: Script variable type changed"));
+EXTERN char e_mismatched_endfunction[]
+	INIT(= N_("E1151: Mismatched endfunction"));
+EXTERN char e_mismatched_enddef[]
+	INIT(= N_("E1152: Mismatched enddef"));

src/testdir/test_vim9_func.vim

@@ -79,6 +79,25 @@ def Test_funcdepth_error()
   set maxfuncdepth&
 enddef
 
+def Test_endfunc_enddef()
+  var lines =<< trim END
+    def Test()
+      echo 'test'
+      endfunc
+    enddef
+  END
+  CheckScriptFailure(lines, 'E1151:', 3)
+
+  lines =<< trim END
+    def Test()
+      func Nested()
+        echo 'test'
+      enddef
+    enddef
+  END
+  CheckScriptFailure(lines, 'E1152:', 4)
+enddef
+
 def ReturnString(): string
   return 'string'
 enddef

src/userfunc.c

@@ -3404,7 +3404,9 @@ define_function(exarg_T *eap, char_u *name_arg)
 
 	    // Check for "endfunction" or "enddef".
 	    if (checkforcmd(&p, nesting_def[nesting]
-			     ? "enddef" : "endfunction", 4) && nesting-- == 0)
+						? "enddef" : "endfunction", 4))
+	    {
+		if (nesting-- == 0)
 		{
 		    char_u *nextcmd = NULL;
 
@@ -3419,9 +3421,9 @@ define_function(exarg_T *eap, char_u *name_arg)
 			     p, TRUE);
 		    if (nextcmd != NULL)
 		    {
-		    // Another command follows. If the line came from "eap" we
+			// Another command follows. If the line came from "eap"
-		    // can simply point into it, otherwise we need to change
+			// we can simply point into it, otherwise we need to
-		    // "eap->cmdlinep".
+			// change "eap->cmdlinep".
 			eap->nextcmd = nextcmd;
 			if (line_to_free != NULL)
 			{
@@ -3432,6 +3434,20 @@ define_function(exarg_T *eap, char_u *name_arg)
 		    }
 		    break;
 		}
+	    }
+
+	    // Check for mismatched "endfunc" or "enddef".
+	    // We don't check for "def" inside "func" thus we also can't check
+	    // for "enddef".
+	    // We continue to find the end of the function, although we might
+	    // not find it.
+	    else if (nesting_def[nesting])
+	    {
+		if (checkforcmd(&p, "endfunction", 4))
+		    emsg(_(e_mismatched_endfunction));
+	    }
+	    else if (eap->cmdidx == CMD_def && checkforcmd(&p, "enddef", 4))
+		emsg(_(e_mismatched_enddef));
 
 	    // Increase indent inside "if", "while", "for" and "try", decrease
 	    // at "end".

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2264,
 /**/
     2263,
 /**/