Yalantis/uCrop · error · CImgArgumentException

load(): Specified filename is (null).

Error message

load(): Specified filename is (null).

What it means

CImg<T>::load(filename) loads an image from disk or network, dispatching on the filename extension. A null filename pointer cannot be inspected, so the method immediately throws CImgArgumentException before attempting any I/O.

Source

Thrown at ucrop/src/main/jni/CImg.h:56447

        }
      }

      disp._normalization = old_normalization;
      if (x1>=0 && x1<x0) cimg::swap(x0,x1);
      if (y1<y0) cimg::swap(y0,y1);
      disp.set_key(okey);
      return CImg<intT>(4,1,1,1,x0,y0,x1>=0?x1 + (int)one:-1,y1);
    }

    //! Load image from a file.
    /**
       \param filename Filename, as a C-string.
       \note The extension of \c filename defines the file format. If no filename
       extension is provided, CImg<T>::get_load() will try to load the file as a .cimg or .cimgz file.
    **/
    CImg<T>& load(const char *const filename) {
      if (!filename)
        throw CImgArgumentException(_cimg_instance
                                    "load(): Specified filename is (null).",
                                    cimg_instance);

      if (!cimg::strncasecmp(filename,"http://",7) || !cimg::strncasecmp(filename,"https://",8)) {
        CImg<charT> filename_local(256);
        load(cimg::load_network(filename,filename_local));
        std::remove(filename_local);
        return *this;
      }

      const char *const ext = cimg::split_filename(filename);
      const unsigned int omode = cimg::exception_mode();
      cimg::exception_mode(0);
      bool is_loaded = true;
      try {
#ifdef cimg_load_plugin
        cimg_load_plugin(filename);
#endif

View on GitHub (pinned to f788b534b4)

Solutions

1. Check for null before calling: if (filename) img.load(filename);
2. Ensure the filename string is initialized/allocated before the call.
3. Load into a std::string first, then pass .c_str() so it can never be null.

Example fix

// before
const char* filename = getenvOptional("IMG"); // may be NULL
img.load(filename);
// after
const char* env = getenvOptional("IMG");
if (env) img.load(env);

if (!filename || !*filename) {
  std::cerr << "No filename provided for load" << std::endl;
  return;
}
img.load(filename);

bool hasFilename(const char* f) { return f != nullptr && f[0] != '\0'; }

try {
  img.load(filename);
} catch (const cimg_library::CImgArgumentException& e) {
  std::cerr << "load() rejected arguments: " << e.what() << std::endl;
}

When it happens

Trigger: Calling load(NULL) directly, or passing a char* filename variable that was never assigned or was freed/set to null after a failed path lookup.

Common situations: Filename built conditionally with one path leaving it null; getConfig-style helpers returning null when a key is missing; passing the result of a failed string conversion straight into load().

Related errors

• load_parrec(): Specified filename is (null).
• load_ascii(): Specified filename is (null).
• load_dlm(): Specified filename is (null).
• load_bmp(): Specified filename is (null).
• load_jpeg(): Specified filename is (null).

AI-assisted analysis of Yalantis/uCrop@f788b534b4 (2026-09-08). Data as JSON: /api/errors/55b93fddd27a560b. Report an issue: GitHub.