SDL_mixer: load_voc.c: Fixed Clang warning (83fb7)

SDL Commits
1 
From 83fb743c6bf94a6af88977a68648d6857bac9840 Mon Sep 17 00:00:00 2001
From: Wohlstand <[EMAIL REDACTED]>
Date: Tue, 31 May 2022 09:30:26 +0300
Subject: [PATCH] load_voc.c: Fixed Clang warning

Clang Code Model noticed the possible recognition of `v.size` as an uninitialized data which may lead to unexpected behavior. Also, make sure `SDL_malloc()` will never be called with a zero value of `v.rest`, and avoid leading division by zero (when `*audio_len` is divided by `v.size`)
(cherry picked from commit 4be422bf8f4b5f531906000db905c1e6f0835b7d)
---
 load_voc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/load_voc.c b/load_voc.c
index f12d4d6e..3ebde36d 100644
--- a/load_voc.c
+++ b/load_voc.c
@@ -392,6 +392,7 @@ SDL_AudioSpec *Mix_LoadVOC_RW (SDL_RWops *src, int freesrc,
     if ( !voc_check_header(src) )
         goto done;
 
+    memset(&v, 0, sizeof (vs_t));
     v.rate = VOC_BAD_RATE;
     v.rest = 0;
     v.has_extended = 0;
@@ -407,12 +408,17 @@ SDL_AudioSpec *Mix_LoadVOC_RW (SDL_RWops *src, int freesrc,
         goto done;
     }
 
+    if (v.size == 0) {
+        SDL_SetError("VOC data had invalid word size!");
+        goto done;
+    }
+
     spec->format = ((v.size == ST_SIZE_WORD) ? AUDIO_S16 : AUDIO_U8);
     if (spec->channels == 0)
         spec->channels = v.channels;
 
     *audio_len = v.rest;
-    *audio_buf = SDL_malloc(v.rest);
+    *audio_buf = (v.rest == 0) ? NULL : SDL_malloc(v.rest);
     if (*audio_buf == NULL)
         goto done;