strbuf: use st_add3() in strbuf_grow()

Simplify the code by calling st_add3() to do overflow checks instead of open-coding it. This changes the error message to include the offending summands, which can be helpful when tracking down the cause. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

René Scharfe committed May 18, 2026 at 22:25 UTC c13d0f7bd4e696d5db3345e00f763df23347b6ad
1 file changed +2 -4
strbuf.c
+2 -4
@@ -106,12 +106,10 @@ void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
106 void strbuf_grow(struct strbuf *sb, size_t extra)
107 {
108 int new_buf = !sb->alloc;
109 - if (unsigned_add_overflows(extra, 1) ||
110 - unsigned_add_overflows(sb->len, extra + 1))
111 - die("you want to use way too much memory");
109 + size_t new_len = st_add3(sb->len, extra, 1);
110 if (new_buf)
111 sb->buf = NULL;
114 - ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
112 + ALLOC_GROW(sb->buf, new_len, sb->alloc);
113 if (new_buf)
114 sb->buf[0] = '\0';
115 }