This is required to make the pointer safely re-usable after being freed,
otherwise the list still says that it has nodes, but they point nowhere.
This is particularly important for libpkgconf, if a caller needs to
re-enter the library after freeing a path in a static path (such as the
default personality)
The current approach was to parse the .pc and, detect the prefix, throw
everything together and at the end replace all \ with / to not produce invalid
escape sequences.
This has the problem that escaping in .pc files is ignored and no longer
possible. Also in case the prefix path has a space in it the result would be
invalid because of missing escaping.
This changes the following things:
* We no longer normalize values at the end. Instead we assume .pc files use "/"
as a directory separator or "\\", same format as under Unix. "\" alone no
longer works. This shouldn't be a problem since most build tools produce .pc
files with "/" like meson, cmake, autotools.
* When injecting the prefix at runtime we convert the prefix to use "/" and
escape spaces so that in combination with the .pc content the result is a
valid escaped path value again.
This patch has been used in MSYS2 for some months now.
See #212
To avoid a crash on some platforms (like Darwin 9) provide a buffer to
realpath(3).
Darwin 9 (last PPC target) documents realpath needs to be given a buffer
to the resolved_path argument large enough to hold PATH_MAX bytes.
With NULL argument it crashes. Solaris makes no mention of
resolved_path to be allowed NULL, yet recent versions accept it and
malloc(3) accordingly.
Because the documentation explicitly mentions PATH_MAX being the limit
to what realpath(3) would write in resolved_path, switching to a static
buffer here doesn't limit resolution compared to dynamically allocating
a buffer by realpath(3).
While this change requires a bit more space on the stack, it avoids a
malloc/free sequence, and allows successful operation on (older)
platforms that lack support for dynamically allocating a return buffer
in realpath(3).
Signed-off-by: Fabian Groffen <grobian@gentoo.org>