Fix Coverity TAINTED_SCALAR in ImageBMP::read (#997)

Resolves: CID-51802

BmpUtils::load_bmp_image[_8u] sets width_/height_ from the BMP file
header and may then return false (e.g. when bounds checks fail or data
read fails).  The previous code called pixels_.resize(size(), 0) and
copy_raw_data(data.get()) unconditionally, which means:

  - On the error path where width_/height_ were set from the file but
    data was not allocated (nullptr), copy_raw_data would perform
    std::copy from a null pointer — undefined behaviour.
  - A malformed BMP with very large dimensions could trigger an
    enormous allocation before the error was returned.

Fix: guard pixels_.resize() and copy_raw_data() with if (!error) in
both ImageBMP<T>::read (generic template) and the ImageBMP<uint8_t>
specialization.  The success path is unaffected; load_bmp_image's
internal bounds checks (height/pitch <= 65536) ensure the dimensions
are safe when !error.

Author: KonstantyMisiak

utils/image/src/image.cpp

@@ -192,8 +192,10 @@ template <typename T> bool ImageBMP<T>::read(const std::string &image_path) {
   bool error = !BmpUtils::load_bmp_image(tmp, width_, height_, pitch,
                                          bits_per_pixel, image_path.c_str());
   data.reset(tmp);
-  pixels_.resize(size(), 0);
-  copy_raw_data(reinterpret_cast<T *>(data.get()));
+  if (!error) {
+    pixels_.resize(size(), 0);
+    copy_raw_data(reinterpret_cast<T *>(data.get()));
+  }
   return error;
 }
 
@@ -203,8 +205,10 @@ template <> bool ImageBMP<uint8_t>::read(const std::string &image_path) {
   bool error =
       !BmpUtils::load_bmp_image_8u(tmp, width_, height_, image_path.c_str());
   data.reset(tmp);
-  pixels_.resize(size(), 0);
-  copy_raw_data(data.get());
+  if (!error) {
+    pixels_.resize(size(), 0);
+    copy_raw_data(data.get());
+  }
   return error;
 }