Re: 21.5 Test Suite Failures - regexp tests

Sean> Stephen J. Turnbull writes: Sean> The problem with regexps is that there are too many border Sean> conditions. You could right 1,000,000 tests, and still miss Sean> one :-( Doesn't mean we shouldn't try to approximate it. If you can thinks of new tests, please don't hesitate to suggest them. (BTW, have you signed, or would you be willing to sign an FSF assignment, for tests? It would be a shame, Martin's theories on test suites not withstanding, if we didn't eventually contribute this to GNU Emacs.) Sean> Ahhh, but my patch moves one `if' to the notwordbound: case, Sean> since it does not make sense in the wordbound: case (and in Sean> fact causes the 'known bug'). That whole approach is wrong, IMHO, because it makes verifying the code twice as hard. At least, I can come up with no conditions where \B != not \b when that code is reached. Thus you only have to check one. With your method, all test cases need to be checked on both paths since they use different code to handle them. Furthermore, your patch probably introduces a crash, because you indeed can "fall off the end" of a Lisp string. There's no guarantee that &string + length(string) is in the data segment, let alone that it is '\000'. (In fact, allowing NUL bytes in strings is one of the reasons why Lisp doesn't use the C representation for strings.) So you _must_ check for AT_STRINGS_END(d) in both cases. Finally, I suspect that \B will fail the corresponding tests using your patch. You've just "moved the bug" into the other branch of execution!:-) Two notes on patch style: don't use // comments in C code; most platforms don't support it. Second, that particular comment is unneeded. If you comment on code written by someone else, it _may_ be appropriate to include some identifier so that you can be asked what in the world you were thinking. But code changes, if accepted, should speak for themselves---if they don't, explain in an explicit comment (and author identity will be in the ChangeLog). -- Institute of Policy and Planning Sciences http://turnbull.sk.tsukuba.ac.jp University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN Ask not how you can "do" free software business; ask what your business can "do for" free software.