mps-cli-py (binary-persistency): fix stream misalignment in cross-module model references#61
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Prithvi686 merged 3 commits intoApr 27, 2026
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… details of the issue and applied fix explained below: - Our binary persistence parser was calling read_string() after reading a MODELID_REGULAR model id but Java's ModelInputStream.readModelReference() calls readModuleReference() there instead but this was missed earlier which caused stream misalignment issues. - This issue wasn't caught earlier since In standard MPS plugin directories this code path is never reached because cross-model references use MODELREF_INDEX but the vemb repo's language plugins specifically migration scripts etc.. most likely use full inline MODELID_REGULAR references which exposed this issue. - Replaced read_string() with _read_module_ref() in _read_other_model_ref() in nodes.py. Affected: 15 .mpb files (migration.mpb, editor.mpb etc..) Result: From 2624 models to 2625 models parsed now and from 11,176,926 nodes to 11,179,666 nodes successfully parsed now without any issues.
Prithvi686
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feature/E3AARCHAI-23402_fix_binary_persistence_parser_stream_misalignment_issue
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15 .mpb files in a big repository (migration.mpb, editor.mpb etc..) were failing to parse with read_bytes(18576): EOF warnings.
Root cause is that -
In _read_other_model_ref() in nodes.py, after reading a MODELID_REGULAR model id, the parser called read_string() but Java's ModelInputStream.readModelReference() calls readModuleReference() there instead.
This was never caught before because standard MPS plugin directories I guess uses MODELREF_INDEX for cross-model refs but the vemb repo's language plugins use full inline MODELID_REGULAR references hitting this path for the first time.
Fix:
Replace read_string() with _read_module_ref() in _read_other_model_ref() in nodes.py.
Result
zero parse warnings
Models read now: From 2624 to 2625
Nodes read now: From 11,176,926 to 11,179,666