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E_STRING_NOT_NULL_TERMINATED
Input string lacks the required null terminator
E_STRING_NOT_NULL_TERMINATED is HRESULT 2147483671 (0x80000017) from winerror.h. AllStat describes it as “String not null terminated.” In the Windows Runtime metadata, object lifetime, asynchronous operation, activation, and apartment model, the code identifies a specific failure boundary and should not be replaced by a generic COM exception.
The caller should keep this result intact through logging, exception translation, and RPC or language projection boundaries.
Where it is encountered
- C++/WinRT, WRL,.NET projections, or native WinRT ABI calls. Record the interface, method, component version, thread, apartment, process, and correlation ID.
- Runtime-class activation, WinMD reflection, asynchronous objects, observable state, or view lifecycle.
- Cross-thread and cross-apartment handoff between UI, ASTA, STA, MTA, broker, and background work.
The immediate focus for it is an ABI boundary that expects a null-terminated string but receives a buffer whose declared extent contains no terminator. Keep it attached to that operation; the same numeric severity outside the owning API does not supply enough context.
Decisive interpretation boundary
Before choosing recovery, verify that the encoding, buffer capacity, producer length, and maximum scan bound are known without reading beyond allocated memory. Validate this condition for it using the owning API state, not an inferred UI symptom.
Also confirm that all observed objects, tokens, buffers, proxies, metadata files, or ACLs belong to the current operation generation and were not retained from an earlier attempt.
Difference from nearby HRESULTs
It is a representation defect; E_BOUNDS describes an attempted range access after bounds are known.
The distinction around it should be represented explicitly in control flow and operational dashboards.
Correct handling and recovery
Reject the buffer, correct the producer, and pass explicit-length string types where the API supports them. Never append a terminator without proving writable capacity.
Backoff alone is not a repair for it; a measurable state or configuration transition must justify another attempt.
Practical scenario
A native extension passes a fixed 64-character array filled completely with text to a WinRT projection. The bridge switches to an explicit length and allocates space for termination.
A regression test should reproduce it, assert the raw HRESULT and all relevant outputs, then correct only the decisive condition and verify the intended success or neighboring failure result.
Lifetime, retry, and cleanup rules
After it, determine whether the current object, interface pointer, call context, token, stream, metadata reader, asynchronous operation, or access-control instance remains valid. Release only resources owned by the failing attempt, cancel callbacks through their documented mechanism, and avoid double close, double commit, repeated activation, or replay of a non-idempotent remote method.
The retry policy for it should state the trigger, maximum attempts, cancellation owner, and reconciliation step for effects that may have completed elsewhere.
References
- Microsoft: C++/WinRT error handling
- Microsoft: concurrency and asynchronous operations
- Microsoft: WinMD files
- Microsoft: IAgileObject
- Microsoft: COM apartments
- Microsoft: HRESULT values
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