h5debug is unable to inspect file with broken root group

[Dave-Allured]

Describe the bug

When invalid root group or invalid superblock is detected, h5debug gives up early with "cannot open file”, and nothing else. This prevents detailed inspection of either superblock or root group, in scenarios when this exact capability is most needed. This behavior is confirmed by examining source code for h5debug and the H5Fopen function.

Please see Forum: HDF5 binary difference for a recent scenario. Due to confidentiality, you must acquire this interesting test file from the original reporter.

Expected behavior

Given a file name and internal object address, h5debug should make best effort to decode and display the file object at that address, regardless of invalid conditions anywhere else in the file.

Platform (please complete the following information)

• HDF5 version: As mentioned in the original conversation, both HDF5 1.4.5 and 2.1.0 have this behavior.
• OS and version: Any
• Compiler and version: Any
• Build system (e.g. CMake version) and generator (e.g. XCode, Ninja): Any

[Dave-Allured]

If my analysis is correct, then it should be easy to create a similar test file by hacking an object header version number in an otherwise valid sample HDF5 file.

[bmribler]

Thank you, @Dave-Allured. The original reporter had given us access to their files.

[vchoi-hdfgroup]

@Dave-Allured you are right that the file cannot be opened is due to bad version number in the root group object header (actually it's all zeroes). Error reporting is disabled in h5debug on entry so it didn't print out the error stacks. So the fix for this issue is to add an option to h5debug to enable error reporting like h5dump.

[Dave-Allured]

So the fix for this issue is to add an option to h5debug to enable error reporting like h5dump.

@vchoi-hdfgroup This is not what I requested. Please see above under "Expected behavior". This is an enhancement request, not simply improved error messaging. Thank you.