Preserve RequestFailedException what() when copying

[Joel Town Road (hippi345)]

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Problem

Azure::Core::RequestFailedException's copy constructor initialized std::runtime_error from other.Message instead of other.what(). Those strings are not the same:

• The string constructor sets what() and leaves Message empty.
• The raw-response constructor sets what() to the HTTP status/reason text and sets Message to the service message field (for example "JT").

A copy therefore replaced what() with Message. Derived types such as Azure::Storage::StorageException inherit this constructor and have the same defect. StorageException does not declare its own copy constructor, so no storage-side change was required.

Fixes #7272

Change

In RequestFailedException(const RequestFailedException&), initialize the base with other.what() so a copy preserves what() and Message exactly. Copy/move assignment operators remain = delete. There are no public API changes.

Because the copy constructor is inline in an installed header, consumers linking a prebuilt binary must rebuild to pick up the fix.

Testing

Added RequestFailedException.CopyPreservesWhatAndMessage in sdk/core/azure-core/test/ut/exception_test.cpp. It builds a RequestFailedException from a RawResponse with a JSON error body (message: "JT"), copies it, and asserts copy.what() and copy.Message equal the original.

Before (unmodified copy constructor) — gtest assertion failure, not a compile error:

[ RUN      ] RequestFailedException.CopyPreservesWhatAndMessage
/workspace/sdk/core/azure-core/test/ut/exception_test.cpp:67: Failure
Expected equality of these values:
  std::string(copy.what())
    Which is: "JT"
  std::string(exception.what())
    Which is: "Received an HTTP unsuccessful status code: 503 Reason: retry please :"
[  FAILED  ] RequestFailedException.CopyPreservesWhatAndMessage (0 ms)

[==========] 4 tests from 1 test suite ran. (0 ms total)
[  PASSED  ] 3 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] RequestFailedException.CopyPreservesWhatAndMessage

After:

[==========] Running 4 tests from 1 test suite.
[----------] 4 tests from RequestFailedException
[ RUN      ] RequestFailedException.JSONError
[       OK ] RequestFailedException.JSONError (0 ms)
[ RUN      ] RequestFailedException.CopyPreservesWhatAndMessage
[       OK ] RequestFailedException.CopyPreservesWhatAndMessage (0 ms)
[ RUN      ] RequestFailedException.JSONErrorNoError
[       OK ] RequestFailedException.JSONErrorNoError (0 ms)
[ RUN      ] RequestFailedException.EmptyValues
[       OK ] RequestFailedException.EmptyValues (0 ms)
[==========] 4 tests from 1 test suite ran. (0 ms total)
[  PASSED  ] 4 tests.

Full azure-core-test binary: 368 tests ran, 330 passed, remaining skipped/disabled (live transport). ctest -R azure-core from sdk/core/azure-core/build/test/ut: 373 discovered tests, exception tests passed; the only CTest failures were pre-existing *_NOT_BUILT placeholders for binaries not built in this targeted azure-core-test compile.

This change was prepared with AI assistance and reviewed by the author.

[github-actions]

Thank you for your contribution Joel Town Road (@hippi345)! We will review the pull request and get back to you soon.

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[Copilot]

🟢 Approval recommended

The focused fix addresses the reported defect with regression coverage and no identified blocking issues.

No open issues 🎉

What changed in this PR

Fixes #7272 by preserving RequestFailedException::what() when copying, including inherited behavior in derived exceptions.

Changes:

• Initializes the copied exception’s base from other.what().
• Adds regression coverage for preserving diagnostics and Message.
• Documents the fix and consumer rebuild requirement.

File	Description
sdk/​core/​azure-core/​test/​ut/​exception_test.cpp	Tests preservation of what() and Message after copying.
sdk/​core/​azure-core/​inc/​azure/​core/​exception.hpp	Corrects the copy constructor’s base initialization.
sdk/​core/​azure-core/​CHANGELOG.md	Records the fix and rebuild requirement.

_{Review effort: Balanced}