Fix benign off-by-one

Previously we always reserved one more byte than necessary in the sprintf output string.
Merged: https://github.com/ruby/ruby/pull/12029
2024-10-23 22:32:55 -07:00 · 2024-10-23 22:32:55 -07:00 · c8c94bfb1e · 2024-11-09 01:39:37 +00:00
commit c8c94bfb1e
parent 1f6dd9071c
1 changed files with 2 additions and 1 deletions
--- a/sprintf.c
+++ b/sprintf.c
@ -67,7 +67,8 @@ sign_bits(int base, const char *p)

 #define CHECK(l) do {\
    int cr = ENC_CODERANGE(result);\
-    while ((l) >= bsiz - blen) {\
+    RUBY_ASSERT(bsiz >= blen); \
+    while ((l) > bsiz - blen) {\
        bsiz*=2;\
        if (bsiz<0) rb_raise(rb_eArgError, "too big specifier");\
    }\