core: fix integer overflow with decimal numbers in calculation of expression

ChangeLog.adoc

@@ -20,6 +20,7 @@ https://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 
 Bug fixes::
 
+  * core: fix integer overflow with decimal numbers in calculation of expression
   * core, plugins: fix integer overflow in loops (issue #2178)
   * core: fix crash in case of NULL message sent to function gui_chat_printf_y_date_tags (issue #1883)
 

src/core/wee-calc.c

@@ -336,9 +336,9 @@ calc_expression (const char *expr)
     struct t_arraylist *list_values, *list_ops;
     const char *ptr_expr, *ptr_expr2;
     char str_result[64], *ptr_operator, *operator;
-    int index_op, decimals;
+    int index_op;
     enum t_calc_symbol last_symbol;
-    double value, factor, *ptr_value;
+    double value, factor, decimals, *ptr_value;
 
     list_values = NULL;
     list_ops = NULL;