patch 8.2.0111: VAR_SPECIAL is also used for booleans

Problem:    VAR_SPECIAL is also used for booleans.
Solution:   Add VAR_BOOL for better type checking.
diff --git a/src/viminfo.c b/src/viminfo.c
index 308a9a6..24cd4f7 100644
--- a/src/viminfo.c
+++ b/src/viminfo.c
@@ -1233,7 +1233,12 @@
 		    (void)string2float(tab + 1, &tv.vval.v_float);
 #endif
 		else
+		{
 		    tv.vval.v_number = atol((char *)tab + 1);
+		    if (type == VAR_SPECIAL && (tv.vval.v_number == VVAL_FALSE
+					     || tv.vval.v_number == VVAL_TRUE))
+			tv.v_type = VAR_BOOL;
+		}
 		if (type == VAR_DICT || type == VAR_LIST)
 		{
 		    typval_T *etv = eval_expr(tv.vval.v_string, NULL);
@@ -1312,12 +1317,13 @@
 	    {
 		switch (this_var->di_tv.v_type)
 		{
-		    case VAR_STRING: s = "STR"; break;
-		    case VAR_NUMBER: s = "NUM"; break;
-		    case VAR_FLOAT:  s = "FLO"; break;
-		    case VAR_DICT:   s = "DIC"; break;
-		    case VAR_LIST:   s = "LIS"; break;
-		    case VAR_BLOB:   s = "BLO"; break;
+		    case VAR_STRING:  s = "STR"; break;
+		    case VAR_NUMBER:  s = "NUM"; break;
+		    case VAR_FLOAT:   s = "FLO"; break;
+		    case VAR_DICT:    s = "DIC"; break;
+		    case VAR_LIST:    s = "LIS"; break;
+		    case VAR_BLOB:    s = "BLO"; break;
+		    case VAR_BOOL:    s = "XPL"; break;  // backwards compat.
 		    case VAR_SPECIAL: s = "XPL"; break;
 
 		    case VAR_UNKNOWN:
@@ -1328,8 +1334,10 @@
 				     continue;
 		}
 		fprintf(fp, "!%s\t%s\t", this_var->di_key, s);
-		if (this_var->di_tv.v_type == VAR_SPECIAL)
+		if (this_var->di_tv.v_type == VAR_BOOL
+				      || this_var->di_tv.v_type == VAR_SPECIAL)
 		{
+		    // do not use "v:true" but "1"
 		    sprintf((char *)numbuf, "%ld",
 					  (long)this_var->di_tv.vval.v_number);
 		    p = numbuf;