patch 8.2.4985: PVS warns for possible array underrun

Problem:    PVS warns for possible array underrun.
Solution:   Add a check for a positive value. (closes #10451)

src/spell.c

@@ -253,7 +253,7 @@ spell_check(
 							     MAXWLEN + 1);
     mi.mi_fwordlen = (int)STRLEN(mi.mi_fword);
 
-    if (camel_case)
+    if (camel_case && mi.mi_fwordlen > 0)
 	// Introduce a fake word end space into the folded word.
 	mi.mi_fword[mi.mi_fwordlen - 1] = ' ';
 

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4985,
 /**/
     4984,
 /**/