From 204d1f560fc3bd001f2c7ae91905d165b6d55f61 Mon Sep 17 00:00:00 2001
From: bnnm <bananaman255@gmail.com>
Date: Sat, 8 Jul 2023 10:53:12 +0200
Subject: [PATCH] Fix TXTH dynamic chunks in some cases

---
 src/meta/txth.c            | 9 ++++++++-
 src/meta/txth_streamfile.h | 8 +++++---
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/meta/txth.c b/src/meta/txth.c
index 73995bf8..6cc2a04e 100644
--- a/src/meta/txth.c
+++ b/src/meta/txth.c
@@ -142,6 +142,8 @@ typedef struct {
     int chunk_start_set;
     int chunk_size_set;
     int chunk_count_set;
+    int chunk_bsize_set;
+    int chunk_dsize_set;
 
     uint32_t base_offset;
     uint32_t is_offset_absolute;
@@ -827,7 +829,8 @@ static void set_body_chunk(txth_header* txth) {
     //todo maybe should only be done once, or have some count to retrigger to simplify?
     if (!txth->chunk_start_set || !txth->chunk_size_set || !txth->chunk_count_set)
         return;
-    if (txth->chunk_size == 0 && !(txth->chunk_bsize_offset || txth->chunk_dsize_offset))
+
+    if (txth->chunk_size == 0 && !(txth->chunk_bsize_set || txth->chunk_dsize_set))
         return;
     if (txth->chunk_start > txth->data_size || txth->chunk_count == 0)
         return;
@@ -853,6 +856,8 @@ static void set_body_chunk(txth_header* txth) {
         cfg.chunk_bsize_offset = txth->chunk_bsize_offset;
         cfg.chunk_dsize_offset = txth->chunk_dsize_offset;
         cfg.chunk_be = txth->chunk_big_endian;
+        cfg.chunk_bsize_set = txth->chunk_bsize_set;
+        cfg.chunk_dsize_set = txth->chunk_dsize_set;
 
         cfg.chunk_start = txth->chunk_start;
         cfg.chunk_size = txth->chunk_size;
@@ -1473,10 +1478,12 @@ static int parse_keyval(STREAMFILE* sf_, txth_header* txth, const char* key, cha
     else if (is_string(key,"chunk_size_offset")) {
         if (!parse_num(txth->sf_head,txth,val, &txth->chunk_bsize_offset)) goto fail;
         txth->chunk_size_set = 1;
+        txth->chunk_bsize_set = 1;
     }
     else if (is_string(key,"chunk_data_size_offset")) {
         if (!parse_num(txth->sf_head,txth,val, &txth->chunk_dsize_offset)) goto fail;
         txth->chunk_size_set = 1;
+        txth->chunk_dsize_set = 1;
     }
     else if (is_string(key,"chunk_endianness")) {
         if (!parse_endianness(txth, val, &txth->chunk_big_endian, NULL)) goto fail;
diff --git a/src/meta/txth_streamfile.h b/src/meta/txth_streamfile.h
index 7816ea3b..604550eb 100644
--- a/src/meta/txth_streamfile.h
+++ b/src/meta/txth_streamfile.h
@@ -17,6 +17,8 @@ typedef struct {
     uint32_t chunk_bsize_offset;
     uint32_t chunk_dsize_offset;
     int chunk_be;
+    int chunk_bsize_set;
+    int chunk_dsize_set;
 } txth_io_config_data;
 
 typedef struct {
@@ -72,15 +74,15 @@ static size_t txth_io_read(STREAMFILE* sf, uint8_t* dest, off_t offset, size_t l
             }
 
             /* chunk size reader (overwrites the above) */
-            if (data->cfg.chunk_header_size && (data->cfg.chunk_bsize_offset || data->cfg.chunk_dsize_offset)) {
+            if (data->cfg.chunk_header_size && (data->cfg.chunk_bsize_set || data->cfg.chunk_dsize_set)) {
                 read_u32_t read_u32 = data->cfg.chunk_be ? read_u32be : read_u32le;
 
                 data->block_size = 0;
                 data->data_size = 0;
 
-                if (data->cfg.chunk_bsize_offset)
+                if (data->cfg.chunk_bsize_set)
                     data->block_size = read_u32(data->physical_offset + data->cfg.chunk_bsize_offset, sf);
-                if (data->cfg.chunk_dsize_offset)
+                if (data->cfg.chunk_dsize_set)
                     data->data_size = read_u32(data->physical_offset + data->cfg.chunk_dsize_offset, sf);
 
                 if (!data->block_size && !data->data_size) { /* bad read? */