vl: Avoid to close stdout after finish 'writeconfig' option

After finish 'writeconfig' to stdout (with '-'), we want to copy/past the related information mannually, not for redirection ('readconfig' does not support '-').

So we can not close the stdout, or next options which may use stdout will not be displayed.

---
 vl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

index 9975e5a..215467f 100644
@@ -3855,7 +3855,9 @@ int main(int argc, char **argv, char **envp)
                         }
                     }
                     qemu_config_write(fp);
-                    fclose(fp);
+                    if (fp != stdout) {
+                        fclose(fp);
+                    }
                     break;
                 }
             case QEMU_OPTION_qtest:

1.7.11.7

Grammar, and awkward to read. May I suggest:

vl: avoid closing stdout with 'writeconfig'

'writeconfig' supports output to stdout (with '-'); when that happens, we must not close stdout, or further command line options that also use stdout will be impacted. (Although 'writeconfig' was copied from 'readconfig', the latter does not have the problem because it does not support reading from '-')

With the improved commit message,

Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

OK, it sounds fine to me, I shall send patch v2 for it.

Thanks.

Chen Gang

Open, share, and attitude like air, water, and life which God blessed

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Am 21.04.2014 17:09, schrieb Eric Blake:

Eric, did you intentionally request to change "Avoid" to lowercase? I was once pointed to https://wiki.gnome.org/Git/CommitMessages as a template, and starting an English-language heading with an uppercase letter seems natural, with anything else being too lazy to press Shift.

Personally I find -writeconfig the most straightforward way to indicate it's an option, just like () makes clear something is a function. The original subject had an explicit "option", that got lost for v2.

Regards,
Andreas

- --
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
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Yes, out of habit, and in comparison to many recent commits. In fact, looking at the current qemu.git head 'git shortlog -100 2d03b49c' shows:

3 commits matching '\.$', 97 without
75 commits matching ': [A-Z]', 24 matching ': [a-z]' (some overlap here, and merge commits don't match either)

extending further to 1000 commits:

21 commits with trailing dot, 979 without
644 matching ': [A-Z]', 260 matching ': [a-z]'

at 10000, things are a bit more even:
5187 matching ': [A-Z]', 3904 matching ': [a-z]'

but still a distinct leaning towards capital at the start of the message

Hmm, maybe we should update the qemu wiki?
http://wiki.qemu.org/Contribute/SubmitAPatch doesn't mention the qemu preferred style (you pointed to the GNOME style, but at least GNU coreutils explicitly prefers lowercase).

At any rate, I'm not going to reject a patch based on capitalization, and can retrain my fingers to use a capital if that is the documented preference.

Good call, so maybe:

vl: Avoid closing stdout with '-writeconfig'

Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

Yeah, it doesn't really seem worth trying to enforce niceties of style here -- the effort required doesn't seem to really match the benefit, and we already have a lot of hoops we make new submitters jump through. "[file or area being patched]: [reasonably descriptive short summary]" is about the limit I personally feel comfortable insisting on.

thanks
-- PMM

So, given this discussion, I enhanced the existing paragraph in the wiki page mentioned above to include a couple more sentences:

'''Write a good commit message'''. QEMU follows the usual standard for git commit messages: the first line (which becomes the email subject line) is "subsystem: single line summary of change". Whether the "single line summary of change" starts with a capital is a matter of taste, but we prefer that the summary does not end in ".". Look at <code>git short-log 30</code> for an idea of sample subject lines. Then there is a blank line and a more detailed description of the patch, another blank and your Signed-off-by: line. The body of the commit message is a good place to document why your change is important. Don't include comments like "This is a suggestion for fixing this bug" (they can go below the "---" line in the email so they don't go into the final commit message).

Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org