SDL_mixer: decoder_flac.c: fix more -Wsign-compare warnings missed in prev. commit

SDL Commits
1 
From e46ac2acabe84109b16e35764ed29bebb2af5e8a Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Fri, 9 Jan 2026 01:45:55 +0300
Subject: [PATCH] decoder_flac.c: fix more -Wsign-compare warnings missed in
 prev. commit

---
 src/decoder_flac.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/decoder_flac.c b/src/decoder_flac.c
index a2229d7d..d6ef83fb 100644
--- a/src/decoder_flac.c
+++ b/src/decoder_flac.c
@@ -176,7 +176,7 @@ static FLAC__StreamDecoderWriteStatus FLAC_IoWrite(const FLAC__StreamDecoder *de
 
     const MIX_OggLoop *loop = &tdata->adata->loop;
     if (tdata->current_iteration < 0) {
-        if (loop->active && ((tdata->current_iteration_frames + amount) >= loop->start)) {
+        if (loop->active && ((tdata->current_iteration_frames + (Sint64)amount) >= loop->start)) {
             tdata->current_iteration = 0;  // we've hit the start of the loop point.
             tdata->current_iteration_frames = (tdata->current_iteration_frames - loop->start);  // so adding `amount` corrects this later.
         }
@@ -186,12 +186,12 @@ static FLAC__StreamDecoderWriteStatus FLAC_IoWrite(const FLAC__StreamDecoder *de
         SDL_assert(loop->active);
         SDL_assert(tdata->current_iteration_frames <= loop->len);
         const Sint64 available = loop->len - tdata->current_iteration_frames;
-        if (amount > available) {
+        if ((Sint64)amount > available) {
             amount = available;
         }
 
         SDL_assert(tdata->current_iteration_frames <= loop->len);
-        if ((tdata->current_iteration_frames + amount) >= loop->len) {  // time to loop?
+        if ((tdata->current_iteration_frames + (Sint64)amount) >= loop->len) {  // time to loop?
             bool should_loop = false;
             if (loop->count < 0) {  // negative==infinite loop
                 tdata->current_iteration = 0;