In GetMagickModulePath add support for registry path that is decided by an .msi

[vilhjalmur]

Is your feature request related to a problem? Please describe.

I changed GetMagickModulePath to support a registry path that is decided when users install my program which loads ImageMagick dll files at runtime that are built by myself. But I have to change this function everytime I upgrade to a new version of ImageMagick.

Describe the solution you'd like

Could this functionality be added and for example be enabled by a define?

static MagickBooleanType GetMagickModulePath(const char *filename,
  MagickModuleType module_type,char *path,ExceptionInfo *exception)
{
  const char
    *registery_key;
  unsigned char
    *key_value;
  DWORD success = 1;
  char package_key[MagickPathExtent];
  DWORD size, type;
  HKEY registry_key;
  LONG status;
  unsigned char *value;

  (void)module_type; // Mark the parameter as intentionally unused

  assert(filename != (const char *)NULL);
  (void)LogMagickEvent(TraceEvent, GetMagickModule(), "%s", filename);
  assert(path != (char *)NULL);
  assert(exception != (ExceptionInfo *)NULL);
  if (strchr(filename, '/') != (char *)NULL)
    return(MagickFalse);
  (void)CopyMagickString(path, filename, MagickPathExtent);

  /*
  Locate path via registry key.
  */
  registery_key = "ImageMagickPath";

  /*
  Look-up base key.
  */
  (void)CopyMagickString(package_key, "SOFTWARE\\DMM Solutions\\DMM\\3.1", MagickPathExtent);
  (void)LogMagickEvent(ConfigureEvent, GetMagickModule(), "%s", package_key);
  registry_key = (HKEY)INVALID_HANDLE_VALUE;
  status = RegOpenKeyExA(HKEY_LOCAL_MACHINE, package_key, 0, KEY_READ, &registry_key);
  key_value = ((unsigned char*)NULL);
  if (status != ERROR_SUCCESS)
  {
    registry_key = (HKEY)INVALID_HANDLE_VALUE;    
    success = 0;
  }
  if (success != 0)
  {
    /*
    Look-up sub key.
    */
    size = 32;
    value = (unsigned char *)AcquireQuantumMemory(size, sizeof(*value));
    if (value == (unsigned char *)NULL)
    {
      RegCloseKey(registry_key);      
      success = 0;
    }
    if (success != 0)
    {
      (void)LogMagickEvent(ConfigureEvent, GetMagickModule(), "%s", registery_key);
      status = RegQueryValueExA(registry_key, registery_key, 0, &type, value, &size);
      if ((status == ERROR_MORE_DATA) && (type == REG_SZ))
      {
        value = (unsigned char *)ResizeQuantumMemory(value, size, sizeof(*value));
        if (value == (BYTE *)NULL)
        {
          RegCloseKey(registry_key);          
          success = 0;
        }
        status = RegQueryValueExA(registry_key, registery_key, 0, &type, value, &size);
      }
      if (success != 0)
      {
        RegCloseKey(registry_key);
        if ((type != REG_SZ) || (status != ERROR_SUCCESS))
          value = (unsigned char *)RelinquishMagickMemory(value);
        key_value = ((unsigned char *)value);
      }
    }
  }
  if (key_value == (unsigned char *)NULL)
  {
    ThrowMagickException(exception, GetMagickModule(), ConfigureError, "RegistryKeyLookupFailed", "`%s'", registery_key);
    return(MagickFalse);
  }
  (void)FormatLocaleString(path, MagickPathExtent, "%s%s%s", (char *)key_value, DirectorySeparator, filename);
  key_value = (unsigned char *)RelinquishMagickMemory(key_value);
  if (IsPathAccessible(path) == MagickFalse)
  {
    ThrowFileException(exception, ConfigureWarning, "UnableToOpenModuleFile", path);
    return(MagickFalse);
  }
  return(MagickTrue);
}

Describe alternatives you've considered

No response

Additional context

No response

[dlemstra]

You seem to have a heavily patched version of our GetMagickModulePath method. Have you tried setting the environment variables when you start your application. That should probably also work?