Bug 14443 – [REG2.067.0] Incorrect double freeing of reference counted struct

cat > bug.d << CODE import std.typecons; struct Path { struct Payload { int p; } RefCounted!Payload _data; unittest { auto path = Path(RefCounted!Payload(12)); assert(path._data.p == 12); foreach(element; PathRange(path)) {} } } struct PathRange { Path path; size_t i; @property empty() { return i > 2; } void popFront() { ++i; } @property PathElement front() { return PathElement(this, path._data.p); } } struct PathElement { PathRange range; this(PathRange range, int) { this.range = range; } } CODE dmd -main -unittest -run bug ---- This code works with 2.066.1 but segfaults with 2.067.0, apparently because the refcount of _data in path drops to 0 while it's still used. My malloc implementation also complains about a double free.

Regression was apparently introduced with https://github.com/D-Programming-Language/dmd/pull/4078.

Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/46841af5b6ac2ceb60a897974423d6f31b8a8301 fix Issue 14443 - Incorrect double freeing of reference counted struct After the issue 13586 fix (pull#4078), the emission of 'prefix' expressions on `CallExp` had accidentally changed `valueNoDtor()` in `ReturnStatement::semantic()` no-op. Then excessive destructor call had happened in PathRange.front(). https://github.com/D-Programming-Language/dmd/commit/c46be675fd3be445dcb0db691a544898aa0332ee Merge pull request #4595 from 9rnsr/fix14443 [REG2.067] Issue 14443 - Incorrect double freeing of reference counted struct

Commit pushed to stable at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/ee257090f0f89adf19eadc70692070c6d30ebac1 Merge pull request #4595 from 9rnsr/fix14443 [REG2.067] Issue 14443 - Incorrect double freeing of reference counted struct

Commit pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/ee257090f0f89adf19eadc70692070c6d30ebac1 Merge pull request #4595 from 9rnsr/fix14443

Commits pushed to stable at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/46841af5b6ac2ceb60a897974423d6f31b8a8301 fix Issue 14443 - Incorrect double freeing of reference counted struct https://github.com/D-Programming-Language/dmd/commit/c46be675fd3be445dcb0db691a544898aa0332ee Merge pull request #4595 from 9rnsr/fix14443