compress: ensure that tile width is not less than code block width

Author: Grok Compression

src/lib/core/t1/part1/Coder.cpp

@@ -43,6 +43,11 @@ bool Coder::preCompress(CompressBlockExec* block, uint32_t& maximum)
     grklog.error("Unable to compress degenerate code block of dimensions %ux%u", w, h);
     return false;
   }
+  if(block->tile_width < w)
+  {
+    grklog.error("Tile width %u less than code block width %u", block->tile_width, w);
+    return false;
+  }
   if(!blockCoder_->alloc(w, h))
     return false;
   auto tileLineAdvance = block->tile_width - w;

src/lib/core/t1/part15/CoderOJPH.cpp

@@ -107,12 +107,14 @@ T1OJPH::~T1OJPH()
   delete allocator;
   delete elastic_alloc;
 }
-void T1OJPH::preCompress([[maybe_unused]] CompressBlockExec* block)
+bool T1OJPH::preCompress([[maybe_unused]] CompressBlockExec* block)
 {
   auto cblk = block->cblk;
   auto w = cblk->width();
   auto h = cblk->height();
   uint32_t tile_width = block->tile_width;
+  if(tile_width < w)
+    return false;
   auto tileLineAdvance = tile_width - w;
   uint32_t cblk_index = 0;
   int32_t shift = 31 - (block->k_msbs + 1);
@@ -152,10 +154,12 @@ void T1OJPH::preCompress([[maybe_unused]] CompressBlockExec* block)
       tiledp += tileLineAdvance;
     }
   }
+  return true;
 }
 bool T1OJPH::compress(CompressBlockExec* block)
 {
-  preCompress(block);
+  if(!preCompress(block))
+    return false;
 
   coded_lists* next_coded = nullptr;
   auto cblk = block->cblk;

src/lib/core/t1/part15/CoderOJPH.h

@@ -35,7 +35,7 @@ class T1OJPH : public ICoder
   bool decompress(DecompressBlockExec* block) override;
 
 private:
-  void preCompress(CompressBlockExec* block);
+  bool preCompress(CompressBlockExec* block);
   bool postProcess(DecompressBlockExec* block);
 
   uint32_t coded_data_size;