patch 8.1.1371: cannot recover from a swap file

Problem:    Cannot recover from a swap file.
Solution:   Do not expand environment variables in the swap file name.
            Do not check the extension when we already know a file is a swap
            file.  (Ken Takata, closes 4415, closes #4369)
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 0174fd6..040514c 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -7002,7 +7002,8 @@
 		copy_option_part(&p, NameBuff, MAXPATHL, ",");
 		mustfree = FALSE;
 		rt = vim_getenv((char_u *)"VIMRUNTIME", &mustfree);
-		if (rt != NULL && fullpathcmp(rt, NameBuff, FALSE) != FPC_SAME)
+		if (rt != NULL &&
+			    fullpathcmp(rt, NameBuff, FALSE, TRUE) != FPC_SAME)
 		{
 		    int		fcount;
 		    char_u	**fnames;
@@ -7224,7 +7225,7 @@
      */
     ga_init2(&ga, (int)sizeof(char_u *), 100);
     if (add_help_tags || fullpathcmp((char_u *)"$VIMRUNTIME/doc",
-						      dir, FALSE) == FPC_SAME)
+						dir, FALSE, TRUE) == FPC_SAME)
     {
 	if (ga_grow(&ga, 1) == FAIL)
 	    got_int = TRUE;