Never shrink bignum on realloc

jhawthorn · jhawthorn · commit 930afa1c7ba7 · 2025-12-05T06:21:17.000-08:00
As far as I can tell, this only ever shrinks by one, and it's really not
worth the expensive realloc for that.
diff --git a/bignum.c b/bignum.c
@@ -3048,7 +3048,7 @@ rb_big_realloc(VALUE big, size_t len)
             if (BIGNUM_LEN(big) == 0) {
                 RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
             }
-            else {
+            else if (BIGNUM_LEN(big) < len) {
                 REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len);
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -3048,7 +3048,7 @@ rb_big_realloc(VALUE big, size_t len)`
`3048`	`3048`	`if (BIGNUM_LEN(big) == 0) {`
`3049`	`3049`	`RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);`
`3050`	`3050`	`}`
`3051`		`- else {`
	`3051`	`+ else if (BIGNUM_LEN(big) < len) {`
`3052`	`3052`	`REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len);`
`3053`	`3053`	`}`
`3054`	`3054`	`}`