When a data filter encounters an error, any error messages posted by that filter are no longer printed to stderr. It still returns an error to the library, and the library prints its internal error messages, but there is no information about what caused the failure in the filter. This can be seen for instance if the flether32 checksum filter is enabled and a checksum doesn't match. This can be seen in both built in filters and external filters that use the default error stack.
This is happening because, in preparation for thread safety work, the library saves the error stack before making a call to a plugin (potentially an application callback), and then restores the stack afterwards, therefore overwriting any changes to the error stack that happened during the call to the plugin.
When a data filter encounters an error, any error messages posted by that filter are no longer printed to stderr. It still returns an error to the library, and the library prints its internal error messages, but there is no information about what caused the failure in the filter. This can be seen for instance if the flether32 checksum filter is enabled and a checksum doesn't match. This can be seen in both built in filters and external filters that use the default error stack.
This is happening because, in preparation for thread safety work, the library saves the error stack before making a call to a plugin (potentially an application callback), and then restores the stack afterwards, therefore overwriting any changes to the error stack that happened during the call to the plugin.