eval_error.c: fix off-by-one error for --backtrace-limit

mame · mame · commit eee93bc9330c · 2020-12-21T11:40:48.000+09:00
https://bugs.ruby-lang.org/issues/17413
diff --git a/eval_error.c b/eval_error.c
@@ -253,9 +253,9 @@ print_backtrace(const VALUE eclass, const VALUE errat, const VALUE str, int reve
         }
 
         // skip for explicit limit
-        if (rb_backtrace_length_limit >= 0 && len > rb_backtrace_length_limit + 1) {
+        if (rb_backtrace_length_limit >= 0 && len > rb_backtrace_length_limit + 2) {
             skip_start = rb_backtrace_length_limit + 1;
-            skip_len = len - rb_backtrace_length_limit;
+            skip_len = len - skip_start;
         }
 
 	for (i = 1; i < len; i++) {

Original file line number	Diff line number	Diff line change
`@@ -253,9 +253,9 @@ print_backtrace(const VALUE eclass, const VALUE errat, const VALUE str, int reve`
`253`	`253`	`}`
`254`	`254`
`255`	`255`	`// skip for explicit limit`
`256`		`- if (rb_backtrace_length_limit >= 0 && len > rb_backtrace_length_limit + 1) {`
	`256`	`+ if (rb_backtrace_length_limit >= 0 && len > rb_backtrace_length_limit + 2) {`
`257`	`257`	`skip_start = rb_backtrace_length_limit + 1;`
`258`		`- skip_len = len - rb_backtrace_length_limit;`
	`258`	`+ skip_len = len - skip_start;`
`259`	`259`	`}`
`260`	`260`
`261`	`261`	`for (i = 1; i < len; i++) {`