From 976e9ef2e7ec0acafe93dc00f809e8871f17a3a3 Mon Sep 17 00:00:00 2001
From: Martin Pulec <martin.pulec@cesnet.cz>
Date: Wed, 18 Jun 2025 12:05:22 +0200
Subject: [PATCH] vcomp/lavc: fix init fail

Due to recent changes, libavcodec initialization fails because trying
to register the lavc module prior to vcomp.

This crashes due to the recent changes but it has been a dark zone so far.

Initialize the vcomp module correctly prior to the lavc.

+ add assert to module_register that would catch this problem
---
 src/module.c           |  1 +
 src/video_compress.cpp | 19 +++++++++++--------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/module.c b/src/module.c
index 2ae63576c..590f66698 100644
--- a/src/module.c
+++ b/src/module.c
@@ -90,6 +90,7 @@ void module_register(struct module *module_data, struct module *parent)
         if (parent == NULL) {
                 return;
         }
+        assert(parent->module_priv != NULL);
         module_priv->parent = parent->module_priv;
         module_mutex_lock(&parent->module_priv->lock);
         simple_linked_list_append(parent->module_priv->children, module_priv);
diff --git a/src/video_compress.cpp b/src/video_compress.cpp
index d02055fe0..0471b7965 100644
--- a/src/video_compress.cpp
+++ b/src/video_compress.cpp
@@ -99,8 +99,17 @@ public:
  * state. The point of doing this is to allow dynamic reconfiguration of the real state.
  */
 struct compress_state {
+        explicit compress_state(struct module *parent)
+        {
+                module_init_default(&mod);
+                mod.cls       = MODULE_CLASS_COMPRESS;
+                mod.priv_data = this;
+                module_register(&mod, parent);
+        }
+        ~compress_state() { module_done(&mod); }
+
         struct module mod;               ///< compress module data
-        struct compress_state_real *ptr; ///< pointer to real compress state
+        struct compress_state_real *ptr{}; ///< pointer to real compress state
         synchronized_queue<shared_ptr<video_frame>, 1> queue;
         bool poisoned = false;
 };
@@ -195,11 +204,7 @@ static void compress_process_message(struct compress_state *proxy, struct msg_ch
  */
 int compress_init(struct module *parent, const char *config_string, struct compress_state **state) {
         struct compress_state *proxy;
-        proxy = new struct compress_state();
-
-        module_init_default(&proxy->mod);
-        proxy->mod.cls = MODULE_CLASS_COMPRESS;
-        proxy->mod.priv_data = proxy;
+        proxy = new struct compress_state(parent);
 
         try {
                 proxy->ptr = compress_state_real::create(&proxy->mod, config_string, proxy);
@@ -208,7 +213,6 @@ int compress_init(struct module *parent, const char *config_string, struct compr
                 return i;
         }
 
-        module_register(&proxy->mod, parent);
 
         *state = proxy;
         return 0;
@@ -497,7 +501,6 @@ compress_done(struct compress_state *proxy)
         }
 
         delete s;
-        module_done(&proxy->mod);
         delete proxy;
 }