Bug 16385 – std.range: undefined behaviour when skipping over 0xff in string.popFront

This unittest in std.exception: pure @safe unittest { import std.algorithm : equal; import std.range : retro; import std.utf : UTFException; auto str = "hello\xFFworld"; // 0xFF is an invalid UTF-8 code unit auto handled = str.handle!(UTFException, RangePrimitive.access, (e, r) => ' '); // Replace invalid code points with spaces assert(handled.equal("hello world")); // `front` is handled, } fails for me depending on compilation options and platform. This happens because string.popFront uses the intrinsic bsr, but doesn't check the undefined case when the argument is 0.

Commits pushed to master at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/0d213a9288a672721da442c331df955188c5ddb7 Fix issue 16385: do not pass 0 to bsr, it has undefined return value https://github.com/dlang/phobos/commit/d753c8e3773f15647508fd8c30cad964982d2f37 Merge pull request #4729 from rainers/issue16385 Fix issue 16385: std.range: undefined behaviour when skipping over 0xff in string.popFront

Commits pushed to stable at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/0d213a9288a672721da442c331df955188c5ddb7 Fix issue 16385: do not pass 0 to bsr, it has undefined return value https://github.com/dlang/phobos/commit/d753c8e3773f15647508fd8c30cad964982d2f37 Merge pull request #4729 from rainers/issue16385