src-test2/lib/libc/stdlib/realpath.c, branch release/11.2.0

Revert r330897:

2018-03-29T02:50:57Z

This was intended to be a non-functional change. It wasn't. The commit message was thus wrong. In addition it broke arm, and merged crypto related code. Revert with prejudice. This revert skips files touched in r316370 since that commit was since MFCed. This revert also skips files that require $FreeBSD$ property changes. Thank you to those who helped me get out of this mess including but not limited to gonzo, kevans, rgrimes. Requested by: gjb (re)

Partial merge of the SPDX changes

2018-03-14T03:19:51Z

These changes are incomplete but are making it difficult to determine what other changes can/should be merged. No objections from: pfg

MFC r318303:

2017-05-29T12:55:26Z

Style.

MFC r318299:

2017-05-29T12:53:44Z

Simplify cleanup on failure in realpath(3).

MFC r318298:

2017-05-29T12:52:13Z

Fix several buffer overflows in realpath(3), and other minor issues. PR: 219154

realpath(): Properly fail "." or ".." components after non-directories.

2014-04-13T19:48:28Z

If realpath() is called on pathnames like "/dev/null/." or "/dev/null/..", it should fail with [ENOTDIR]. Pathnames like "/dev/null/" already failed as they should. Also, put the check for non-directories after lstatting the previous component instead of when the empty component (consecutive or trailing slashes) is detected, saving an lstat() call and some lines of code. PR: kern/82980 MFC after: 2 weeks

- Correct mispellings of the word occurrence

2013-04-17T11:40:10Z

Submitted by: Christoph Mallon (via private mail)

Avoid mapping ENOENT to ENOTDIR for non-existent path components.

2012-09-12T17:05:39Z

The ENOTDIR mapping was introduced in r235266 for kern/128933 based on an interpretation of the somewhat ambiguous language in the POSIX realpath specification. The interpretation is inconsistent with Solaris and Linux, a regression from 9.0, and does not appear to be permitted by the description of ENOTDIR: 20 ENOTDIR Not a directory. A component of the specified pathname existed, but it was not a directory, when a directory was expected. PR: standards/171577 MFC after: 3 days

1) Although unpublished version of standard

2012-06-05T16:16:33Z

http://austingroupbugs.net/view.php?id=385#c713 (Resolved state) recommend this way for the current standard (called "earlier" in the text) "However, earlier versions of this standard did not require this, and the same example had to be written as: // buf was obtained by malloc(buflen) ret = write(fd, buf, buflen); if (ret < 0) { int save = errno; free(buf); errno = save; return ret; } " from feedback I have for previous commit it seems that many people prefer to avoid mass code change needed for current standard compliance and prefer to track unpublished standard instead, which requires now that free() itself must save errno, not its usage code. So, I back out "save errno across free()" part of previous commit, and will fill PR for changing free() isntead. 2) Remove now unused serrno. MFC after: 1 week

1) IEEE Std 1003.1-2008, "errno" section, is explicit that

2012-06-04T21:34:49Z

"The setting of errno after a successful call to a function is unspecified unless the description of that function specifies that errno shall not be modified." However, free() in IEEE Std 1003.1-2008 does not mention its interaction with errno, so MAY modify it after successful call (it depends on particular free() implementation, OS-specific, etc.). So, save errno across free() calls to make code portable and POSIX-conformant. 2) Remove unused serrno assignment. MFC after: 1 week