SDL: SDL_iostream.c: stdio_seek - skip API call for SEEK_CUR with 0 offset

SDL Commits
1 
From 7d78835f87da50d58f88ad780f838f92fd36634b Mon Sep 17 00:00:00 2001
From: ds-sloth <[EMAIL REDACTED]>
Date: Fri, 16 Aug 2024 17:13:49 -0400
Subject: [PATCH] SDL_iostream.c: stdio_seek - skip API call for SEEK_CUR with
 0 offset

Fixes #10556.
---
 src/file/SDL_iostream.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/file/SDL_iostream.c b/src/file/SDL_iostream.c
index d10de2da7954d..7b7b309349688 100644
--- a/src/file/SDL_iostream.c
+++ b/src/file/SDL_iostream.c
@@ -360,7 +360,10 @@ static Sint64 SDLCALL stdio_seek(void *userdata, Sint64 offset, SDL_IOWhence whe
     }
 #endif
 
-    if (fseek(iodata->fp, (fseek_off_t)offset, stdiowhence) == 0) {
+    /* don't make a possibly-costly API call for the noop seek from SDL_TellIO */
+    const SDL_bool is_noop = (whence == SDL_IO_SEEK_CUR) && (offset == 0);
+
+    if (is_noop || fseek(iodata->fp, (fseek_off_t)offset, stdiowhence) == 0) {
         const Sint64 pos = ftell(iodata->fp);
         if (pos < 0) {
             return SDL_SetError("Couldn't get stream offset");