Fix valgrind and asan memory leaks and crashes.

libavcodec/vorbisdec.c

Index: libavcodec/vorbisdec.c
diff --git a/libavcodec/vorbisdec.c b/libavcodec/vorbisdec.c
index f71d606dadf76d37cc6b161eb0fec869cb3a688a..443c0aac857ab26ba0f915bc333cf41557b85fa2 100644
--- a/libavcodec/vorbisdec.c
+++ b/libavcodec/vorbisdec.c
@@ -197,38 +197,46 @@ static void vorbis_free(vorbis_context *vc)
     av_freep(&vc->channel_floors);
     av_freep(&vc->saved);
 
-    for (i = 0; i < vc->residue_count; i++)
-        av_free(vc->residues[i].classifs);
-    av_freep(&vc->residues);
+    if (vc->residues) {
+        for (i = 0; i < vc->residue_count; i++)
+            av_free(vc->residues[i].classifs);
+        av_freep(&vc->residues);
+    }
     av_freep(&vc->modes);
 
     ff_mdct_end(&vc->mdct[0]);
     ff_mdct_end(&vc->mdct[1]);
 
-    for (i = 0; i < vc->codebook_count; ++i) {
-        av_free(vc->codebooks[i].codevectors);
-        free_vlc(&vc->codebooks[i].vlc);
+    if (vc->codebooks) {
+        for (i = 0; i < vc->codebook_count; ++i) {
+            av_free(vc->codebooks[i].codevectors);
+            free_vlc(&vc->codebooks[i].vlc);
+        }
+        av_freep(&vc->codebooks);
     }
-    av_freep(&vc->codebooks);
 
-    for (i = 0; i < vc->floor_count; ++i) {
-        if (vc->floors[i].floor_type == 0) {
-            av_free(vc->floors[i].data.t0.map[0]);
-            av_free(vc->floors[i].data.t0.map[1]);
-            av_free(vc->floors[i].data.t0.book_list);
-            av_free(vc->floors[i].data.t0.lsp);
-        } else {
-            av_free(vc->floors[i].data.t1.list);
+    if (vc->floors) {
+        for (i = 0; i < vc->floor_count; ++i) {
+            if (vc->floors[i].floor_type == 0) {
+                av_free(vc->floors[i].data.t0.map[0]);
+                av_free(vc->floors[i].data.t0.map[1]);
+                av_free(vc->floors[i].data.t0.book_list);
+                av_free(vc->floors[i].data.t0.lsp);
+            } else {
+                av_free(vc->floors[i].data.t1.list);
+            }
         }
+        av_freep(&vc->floors);
     }
-    av_freep(&vc->floors);
 
-    for (i = 0; i < vc->mapping_count; ++i) {
-        av_free(vc->mappings[i].magnitude);
-        av_free(vc->mappings[i].angle);
-        av_free(vc->mappings[i].mux);
+    if (vc->mappings) {
+        for (i = 0; i < vc->mapping_count; ++i) {
+            av_free(vc->mappings[i].magnitude);
+            av_free(vc->mappings[i].angle);
+            av_free(vc->mappings[i].mux);
+        }
+        av_freep(&vc->mappings);
     }
-    av_freep(&vc->mappings);
 }
 
 // Parse setup header -------------------------------------------------