typelib compiler: properly initialise memory

The typelib compiler was writing uninitialised memory to the output file.

There were two sources of this uninitialised memory: the hash writer included
some uninitialised memory in its output, and the bytes added after the hash
output for padding were also not being initialised.

Fix this by passing the padded size to the hash code writer function and
having that function initialise the entire memory region to zero before
writing.

https://bugzilla.gnome.org/show_bug.cgi?id=721177

2 files changed, 4 insertions, 1 deletions

diff --git a/girepository/girmodule.c b/girepository/girmodule.c
index 05c8987f..e3897c34 100644
--- a/girepository/girmodule.c
+++ b/girepository/girmodule.c
@@ -279,8 +279,9 @@ add_directory_index_section (guint8 *data, GIrModule *module, guint32 *offset2)
   alloc_section (data, GI_SECTION_DIRECTORY_INDEX, *offset2);
 
   required_size = _gi_typelib_hash_builder_get_buffer_size (dirindex_builder);
+  required_size = ALIGN_VALUE (required_size, 4);
 
-  new_offset = *offset2 + ALIGN_VALUE (required_size, 4);
+  new_offset = *offset2 + required_size;
 
   data = g_realloc (data, new_offset);
 
diff --git a/girepository/gthash.c b/girepository/gthash.c
index ecc3b104..831c87e9 100644
--- a/girepository/gthash.c
+++ b/girepository/gthash.c
@@ -158,6 +158,8 @@ _gi_typelib_hash_builder_pack (GITypelibHashBuilder *builder, guint8* mem, guint
   g_assert (len >= builder->packed_size);
   g_assert ((((unsigned long)mem) & 0x3) == 0);
 
+  memset (mem, 0, len);
+
   *((guint32*) mem) = builder->dirmap_offset;
   packed_mem = (guint8*)(mem + sizeof(guint32));
   cmph_pack (builder->c, packed_mem);