SDL_mixer: stb_vorbis: fix decoding appends silence at end (7f4ac)

SDL Commits
1 
From 7f4ac17783c7e36a0005da6ab5270bd2f1670935 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89rico=20Porto?= <[EMAIL REDACTED]>
Date: Sun, 12 Jan 2025 18:50:10 -0300
Subject: [PATCH] stb_vorbis: fix decoding appends silence at end

Reference issue: https://github.com/icculus/SDL_sound/issues/92.

Co-Authored-By: Ozkan Sezer <sezeroz@gmail.com>
(cherry picked from commit 9e31fba105a56a25f57a6ec70f7e8fa25af818f8)
---
 src/codecs/stb_vorbis/stb_vorbis.h | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/codecs/stb_vorbis/stb_vorbis.h b/src/codecs/stb_vorbis/stb_vorbis.h
index 81c13cd1a..ae1c39111 100644
--- a/src/codecs/stb_vorbis/stb_vorbis.h
+++ b/src/codecs/stb_vorbis/stb_vorbis.h
@@ -5512,6 +5512,21 @@ int stb_vorbis_get_frame_short_interleaved(stb_vorbis *f, int num_c, short *buff
    return len;
 }
 
+static int fixup_current_playback_loc(stb_vorbis *f, int n)
+{
+   unsigned int lgs;
+
+   f->current_playback_loc += n;
+   lgs = stb_vorbis_stream_length_in_samples(f);
+   if (f->current_playback_loc > lgs && lgs > 0 && lgs != SAMPLE_unknown) {
+       int r = n - (f->current_playback_loc - (int)lgs);
+       f->current_playback_loc = lgs;
+       return r;
+   }
+
+   return n;
+}
+
 int stb_vorbis_get_samples_short_interleaved(stb_vorbis *f, int channels, short *buffer, int num_shorts)
 {
    float **outputs;
@@ -5528,8 +5543,7 @@ int stb_vorbis_get_samples_short_interleaved(stb_vorbis *f, int channels, short
       if (n == len) break;
       if (!stb_vorbis_get_frame_float(f, NULL, &outputs)) break;
    }
-   f->current_playback_loc += n;
-   return n;
+   return fixup_current_playback_loc(f, n);
 }
 
 int stb_vorbis_get_samples_short(stb_vorbis *f, int channels, short **buffer, int len)
@@ -5546,8 +5560,7 @@ int stb_vorbis_get_samples_short(stb_vorbis *f, int channels, short **buffer, in
       if (n == len) break;
       if (!stb_vorbis_get_frame_float(f, NULL, &outputs)) break;
    }
-   f->current_playback_loc += n;
-   return n;
+   return fixup_current_playback_loc(f, n);
 }
 
 #ifndef STB_VORBIS_NO_STDIO
@@ -5655,8 +5668,7 @@ int stb_vorbis_get_samples_float_interleaved(stb_vorbis *f, int channels, float
       if (!stb_vorbis_get_frame_float(f, NULL, &outputs))
          break;
    }
-   f->current_playback_loc += n;
-   return n;
+   return fixup_current_playback_loc(f, n);
 }
 
 int stb_vorbis_get_samples_float(stb_vorbis *f, int channels, float **buffer, int num_samples)
@@ -5682,8 +5694,7 @@ int stb_vorbis_get_samples_float(stb_vorbis *f, int channels, float **buffer, in
       if (!stb_vorbis_get_frame_float(f, NULL, &outputs))
          break;
    }
-   f->current_playback_loc += n;
-   return n;
+   return fixup_current_playback_loc(f, n);
 }
 #endif // STB_VORBIS_NO_PULLDATA_API