Replace:
if (virBufferError(&buf)) {
    virBufferFreeAndReset(&buf);
    virReportOOMError();
    ...
}

with:
if (virBufferCheckError(&buf) < 0)
    ...

This should not be a functional change (unless some callers
misused the virBuffer APIs - a different error would be reported
then)

To free string lists with some strings stolen from the middle we need to
walk the complete array. Introduce a new helper that takes the string
list size to free such string lists.

To allow using the array manipulation macros on the arrays returned by
virStringSplit we need to know the count of the elements in the array.
Modify virStringSplit to return this value, rename it and add a helper
with the old name so that we don't need to update all the code.

strtoul() is required to parse negative numbers as their
twos-complement positive counterpart.  But sometimes we want
to reject negative numbers.  Add new functions to do this.
The 'p' suffix is a mnemonic for 'positive' (technically it
also parses 0, but 'non-negative' doesn't lend itself to a
nice one-letter suffix).

* src/util/virstring.h (virStrToLong_uip, virStrToLong_ulp)
(virStrToLong_ullp): New prototypes.
* src/util/virstring.c (virStrToLong_uip, virStrToLong_ulp)
(virStrToLong_ullp): New functions.
* src/libvirt_private.syms (virstring.h): Export them.
* tests/virstringtest.c (testStringToLong): Test them.
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit f22b7899 called to light a long-standing latent bug: the
behavior of virStrToLong_ui was different on 32-bit platforms
than on 64-bit platforms.  Curse you, C type promotion and
narrowing rules, and strtoul specification.  POSIX says that for
a 32-bit long, strtol handles only 2^32 values [LONG_MIN to
LONG_MAX] while strtoul handles 2^33 - 1 values [-ULONG_MAX to
ULONG_MAX] with twos-complement wraparound for negatives.  Thus,
parsing -1 as unsigned long produces ULONG_MAX, rather than a
range error.  We WANT[1] this same shortcut for turning -1 into
UINT_MAX when parsing to int; and get it for free with 32-bit
long.  But with 64-bit long, ULONG_MAX is outside the range
of int and we were rejecting it as invalid; meanwhile, we were
silently treating -18446744073709551615 as 1 even though it
textually exceeds INT_MIN.  Too bad there's not a strtoui() in
libc that does guaranteed parsing to int, regardless of the size
of long.

The bug has been latent since 2007, introduced by Jim Meyering
in commit 5d254191 in the attempt to eradicate unsafe use of
strto[u]l when parsing ints and longs.  How embarrassing that we
are only discovering it now - so I'm adding a testsuite to ensure
that it covers all the corner cases we care about.

[1] Ideally, we really want the caller to be able to choose whether
to allow negative numbers to wrap around to their 2s-complement
counterpart, as in strtoul, or to force a stricter input range
of [0 to UINT_MAX] by rejecting negative signs; this will be added
in a later patch for all three int types.

This patch is tested on both 32- and 64-bit; the enhanced
virstringtest passes on both platforms, while virstoragetest now
reliably fails on both platforms instead of just 32-bit platforms.
That test will be fixed later.

* src/util/virstring.c (virStrToLong_ui): Ensure same behavior
regardless of platform long size.
* tests/virstringtest.c (testStringToLong): New function.
(mymain): Comprehensively test string to long parsing.
Signed-off-by: NEric Blake <eblake@redhat.com>

Fix minor typos in source comments
Signed-off-by: NEric Blake <eblake@redhat.com>

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add a virStringReplace method to virstring.{h,c} to perform
substring matching and replacement
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add a virStringSearch method to virstring.{c,h} which performs
a regex match against a string and returns the matching substrings.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Add virStringSortCompare and virStringSortRevCompare as
standard functions to use with qsort.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Make virStringArrayHasString return false when called on a non-existent
string array.

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Actually, I'm turning this function into a macro as filename,
function name and line number needs to be passed. The new
function virAsprintfInternal is introduced with the extended set
of arguments.

When src is NULL, VIR_STRDUP will return 0 directly.
This patch will set dest to NULL before VIR_STRDUP return.

Example:
[root@yds-pc libvirt]# virsh
Welcome to virsh, the virtualization interactive terminal.

Type: 'help' for help with commands
'quit' to quit

virsh # connect
error: Failed to connect to the hypervisor
error: internal error Unable to parse URI �N�*
Signed-off-by: Nyangdongsheng <yangds.fnst@cn.fujitsu.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

It may shorten the code a bit as the following pattern:

  VIR_STRNDUP(dst, src, cond ? n : strlen(src))

is used on several places among our code. However, we can
move the strlen into virStrndup and thus write just:

  VIR_STRNDUP(dst, src, cond ? n : -1)

Since PIDs can be reused, polkit prefers to be given
a (PID,start time) pair. If given a PID on its own,
it will attempt to lookup the start time in /proc/pid/stat,
though this is subject to races.

It is safer if the client app resolves the PID start
time itself, because as long as the app has the client
socket open, the client PID won't be reused.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

While reviewing proposed VIR_STRDUP conversions, I've already noticed
several places that do:

if (str && VIR_STRDUP(dest, str) < 0)

which can be simplified by allowing str to be NULL (something that
strdup() doesn't allow).  Meanwhile, code that wants to ensure a
non-NULL dest regardless of the source can check for <= 0.

Also, make it part of the VIR_STRDUP contract that macro arguments
are evaluated exactly once.

* src/util/virstring.h (VIR_STRDUP, VIR_STRDUP_QUIET, VIR_STRNDUP)
(VIR_STRNDUP_QUIET): Improve contract.
* src/util/virstring.c (virStrdup, virStrndup): Change return
conventions.
* docs/hacking.html.in: Document this.
* HACKING: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

The code adaptation is not done right now, but in subsequent patches.
Hence I am not implementing syntax-check rule as it would break
compilation. Developers are strongly advised to use these new macros.
They are similar to VIR_ALLOC() logic: VIR_STRDUP(dst, src) returns zero
on success, -1 otherwise. In case you don't want to report OOM error,
use the _QUIET variant of a macro.

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NCorey Bryant <coreyb@linux.vnet.ibm.com>
Tested-by: NCorey Bryant <coreyb@linux.vnet.ibm.com>

Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This introduces a few new APIs for dealing with strings.
One to split a char * into a char **, another to join a
char ** into a char *, and finally one to free a char **

There is a simple test suite to validate the edge cases
too. No more need to use the horrible strtok_r() API,
or hand-written code for splitting strings.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>