Abort 'vcl_init' asap if a VMOD object instance cannot be created. See …

…https://varnish-cache.org/lists/pipermail/varnish-dev/2024-September/009853.html & 721aa22

src/helpers.h

@@ -44,4 +44,7 @@ extern vmod_state_t vmod_state;
 #define FAIL_WS(ctx, result) \
     FAIL(ctx, result, "Workspace overflow")
 
+#define FAIL_INSTANCE(ctx, result) \
+    FAIL(ctx, result, "Failed to create instance")
+
 #endif

src/vmod_cfg_file.c

@@ -358,6 +358,10 @@ vmod_file__init(
         }
     }
 
+    if (instance == NULL) {
+        FAIL_INSTANCE(ctx,);
+    }
+
     *file = instance;
 }
 

src/vmod_cfg_rules.c

@@ -259,6 +259,10 @@ vmod_rules__init(
         }
     }
 
+    if (instance == NULL) {
+        FAIL_INSTANCE(ctx,);
+    }
+
     *rules = instance;
 }
 

src/vmod_cfg_script.c

@@ -151,6 +151,10 @@ vmod_script__init(
         }
     }
 
+    if (instance == NULL) {
+        FAIL_INSTANCE(ctx,);
+    }
+
     *script = instance;
 }