The KWSys String implementation of strcasecmp initialized 'result'
immediately before assigning to it. Borland produces a warning in this
case, so this commit removes the extra initialization.
This teaches ConvertToUnixSlashes to convert VMS paths into posix-style
paths. We also set the DECC$FILENAME_UNIX_ONLY feature so the process
always sees posix-style paths on disk.
This achieves basic process execution on OpenVMS. We use work-arounds
for different fork()/exec() behavior and a lack of select().
VMS emulates fork/exec using setjmp/longjmp to evaluate the child and
parent return cases from fork. Therefore both must be invoked from the
same function.
Since select() works only for sockets we use the BeOS-style polling
implementation. However, non-blocking reads on empty pipes cannot be
distinguished easily from the last read on a closed pipe. Therefore we
identify end of data by an empty read after the child terminates.
The Compaq compiler (on VMS) includes 'String.c' in source files that
use the stl string while looking for template definitions. This was the
true cause of double-inclusion of the 'kwsysPrivate.h' header. We work
around the problem by conditionally compiling the entire source file on
a condition only true when really building the source.
The kwsysPrivate header double-inclusion check hits a false positive on
VMS for an undetermined reason. This simplifies the workaround and
documents it.