commit d9cffc5f46b62aeff46eebf51449726386d6c485
author Wan-Teh Chang <wtc@google.com> Sat Jan 29 22:31:01 2022 -0800
committer GitHub <noreply@github.com> Sat Jan 29 22:31:01 2022 -0800
tree 1f904d14fc689af52f215fcadd0f678c4eae212e
parent 891945ce02ace801e9aed67d11a24dd1b46aa5d9

Increment lastItemID first when creating an item (#835)

Fix a bug introduced in commit f732a4d240d1562151685b71e822d0ba3a352ad9.

In avifEncoderDataCreateItem(), increment data->lastItemID before
setting item->id equal to data->lastItemID. This is what the original
code did.

Fix https://github.com/AOMediaCodec/libavif/issues/836.

Bug: https://github.com/AOMediaCodec/libavif/issues/820

src/write.c

diff --git a/src/write.c b/src/write.c
index 3d2efde..657bfaa 100644
--- a/src/write.c
+++ b/src/write.c
@@ -151,6 +151,7 @@
 static avifEncoderItem * avifEncoderDataCreateItem(avifEncoderData * data, const char * type, const char * infeName, size_t infeNameSize, uint32_t cellIndex)
 {
     avifEncoderItem * item = (avifEncoderItem *)avifArrayPushPtr(&data->items);
+    ++data->lastItemID;
     item->id = data->lastItemID;
     memcpy(item->type, type, sizeof(item->type));
     item->infeName = infeName;
@@ -160,11 +161,11 @@
     if (!avifArrayCreate(&item->mdatFixups, sizeof(avifOffsetFixup), 4)) {
         goto error;
     }
-    ++data->lastItemID;
     return item;
 
 error:
     avifCodecEncodeOutputDestroy(item->encodeOutput);
+    --data->lastItemID;
     avifArrayPop(&data->items);
     return NULL;
 }