LibGfx+JPGLoader: Fix decoding outside of LibWeb

The DC reset interval was initialized to garbage :)

Libraries/LibGfx/JPGLoader.cpp

@@ -135,21 +135,21 @@ struct Macroblock {
 };
 
 struct MacroblockMeta {
- u32 total;
- u32 padded_total;
- u32 hcount;
- u32 vcount;
- u32 hpadded_count;
- u32 vpadded_count;
+ u32 total { 0 };
+ u32 padded_total { 0 };
+ u32 hcount { 0 };
+ u32 vcount { 0 };
+ u32 hpadded_count { 0 };
+ u32 vpadded_count { 0 };
 };
 
 struct ComponentSpec {
  i8 id { -1 };
  u8 hsample_factor { 1 }; // Horizontal sampling factor.
  u8 vsample_factor { 1 }; // Vertical sampling factor.
- u8 ac_destination_id;
- u8 dc_destination_id;
- u8 qtable_id; // Quantization table id.
+ u8 ac_destination_id { 0 };
+ u8 dc_destination_id { 0 };
+ u8 qtable_id { 0 }; // Quantization table id.
 };
 
 struct StartOfFrame {
@@ -159,14 +159,14 @@ struct StartOfFrame {
  };
 
  FrameType type { FrameType::Baseline };
- u8 precision;
- u16 height;
- u16 width;
+ u8 precision { 0 };
+ u16 height { 0 };
+ u16 width { 0 };
 };
 
 struct HuffmanTableSpec {
- u8 type;
- u8 destination_id;
+ u8 type { 0 };
+ u8 destination_id { 0 };
  u8 code_counts[16] = { 0 };
  Vector<u8> symbols;
  Vector<u16> codes;
@@ -189,16 +189,16 @@ struct JPGLoadingContext {
  State state { State::NotDecoded };
  const u8* data { nullptr };
  size_t data_size { 0 };
- u32 luma_table[64];
- u32 chroma_table[64];
+ u32 luma_table[64] = { 0 };
+ u32 chroma_table[64] = { 0 };
  StartOfFrame frame;
- u8 hsample_factor;
- u8 vsample_factor;
- bool has_zero_based_ids;
- u8 component_count;
+ u8 hsample_factor { 0 };
+ u8 vsample_factor { 0 };
+ bool has_zero_based_ids { false };
+ u8 component_count { 0 };
  ComponentSpec components[3];
  RefPtr<Gfx::Bitmap> bitmap;
- u16 dc_reset_interval;
+ u16 dc_reset_interval { 0 };
  Vector<HuffmanTableSpec> dc_tables;
  Vector<HuffmanTableSpec> ac_tables;
  HuffmanStreamState huffman_stream;