Fix NPE segfault when "verbose" is enabled

[dhgutteridge]

Prior to revision b606826, log_tag() was only ever invoked when err_fp
was guaranteed to be assigned. After that revision, it could be called
with err_fp being null. Carry some of the old "!verbose" logic into
log_tag() to address this.

[dhgutteridge]

This may be unrelated to #94. I haven't tested that one. The stack
trace in #94 looks rather different. My reproduction details and
(though probably unnecessary here, except to compare with #94)
backtrace follow.

Running "pkgin -V upgrade mate" (on a local repo, not that that
matters) resulted in a segfault on NetBSD -current (9.99.71/amd64).

$ pkgin -V upgrade mate
reading local summary...
processing local summary...
calculating dependencies...done.

156 packages to refresh:
xorg-util-macros-1.19.2 xmlcatmgr-2.2nb1 wayland-1.18.0nb1 swig-1.3.38nb1 shared-mime-info-1.10nb2 rust-bin-1.44.0 re2c-1.1.1
py27-gobject-2.28.7nb2 py27-expat-2.7.18 py-gobject3-common-3.36.1 py-gobject-shared-2.28.7nb4 ptexenc-1.3.8
poppler-includes-0.87.0 perl-5.30.3 pcre-8.44 patchelf-0.10 p5-XML-SAX-Expat-0.51nb5 p5-XML-SAX-Base-1.09nb3 p5-XML-SAX-1.00nb2
p5-XML-NamespaceSupport-1.12nb3 p11-kit-0.23.15nb1 nss-3.55 nettle-3.6 mozjs60-60.8.0nb6 mktexlsr-2020 lzo-2.10 lzip-1.21
lua53-5.3.5 libxslt-1.1.34nb2 libxklavier-5.4nb5 libwnck3-3.24.1nb8 libuuid-2.32.1 libunistring-0.9.10 libunique-1.1.6nb31
libtool-base-2.4.6nb2 libtasn1-4.16.0 librsvg-2.48.3nb1 libpaper-1.1.28 libogg-1.3.4nb1 libindicator-12.10.1nb11
libimagequant-2.12.6 libgnome-keyring-3.12.0nb1 libglade-2.6.4nb34 libfakekey-0.1 libcfg+-0.7.0 libcanberra-0.30nb3 libXft-2.3.3
kpathsea-6.3.2 iso-codes-3.77nb1 intltool-0.51.0nb4 icon-naming-utils-0.8.90nb7 gtksourceview3-3.24.11nb3
gtk2-engines-murrine-0.98.2nb11 gtk2-engines-2.20.2nb28 gtk2+-2.24.32nb14 gstreamer1-1.16.2nb1 gsettings-desktop-schemas-3.24.0nb1
gsed-4.8 gperf-3.1 gnome-doc-utils-0.20.10nb5 gmake-4.2.1nb1 ghostscript-fonts-8.11nb3 getopt-1.1.6 fontconfig-2.13.1
docbook-xml-4.5 digest-20190127 cwrappers-20180325 compat80-8.0 checkperms-1.12 autoconf213-2.13nb8 autoconf-archive-2019.01.06
autoconf-2.69nb9 x11-links-1.31 zziplib-0.13.69 graphviz-2.44.1 gd-2.3.0 atril-1.24.0nb1 gdk-pixbuf2-2.40.0nb1 xcb-util-0.4.0
gucharmap-2.32.1nb30 pluma-1.24.0nb1 desktop-file-utils-0.26 mate-terminal-1.24.0nb1 mate-utils-1.24.0 mate-themes-3.22.21
mate-session-manager-1.24.0 mate-polkit-1.24.0 mate-notification-daemon-1.24.0 mate-netbook-1.24.0 mate-indicator-applet-1.24.0
mate-icon-theme-faenza-1.20.0nb6 mate-icon-theme-1.24.0 mozo-1.24.0 gtk-doc-1.32nb3 engrampa-1.24.0 caja-dropbox-1.24.0
libnotify-0.7.9nb2 itstool-2.0.6nb1 gobject-introspection-1.64.1 libxkbcommon-0.10.0 pango-1.44.7nb2 py37-cairo-1.18.2
py27-cairo-1.18.2 python27-2.7.18 poppler-0.87.0 cairo-1.16.0nb1 mate-desktop-1.24.0 libpeas-1.26.0 gts-0.7.6nb1 gawk-5.0.1
mate-menus-1.24.0 libgtop-2.28.4nb17 vte3-0.60.3nb1 polkit-0.116nb3 libmatekbd-1.24.0nb1 upower-0.99.11 pam-pwauth_suid-1.2nb1
mate-settings-daemon-1.24.0nb1 marco-1.24.1 gnome-keyring-2.32.1nb29 p5-XML-Parser-2.44nb5 p5-XML-Simple-2.25nb2 enchant2-2.2.8nb1
p5-gettext-1.07nb4 GConf-3.2.3nb5 py37-pygments-2.5.2 py37-anytree-2.8.0 pkgconf-1.6.0 py27-libxslt-1.1.34nb1
py27-libxml2-2.9.10nb1 ORBit2-2.14.19nb5 dbus-glib-0.110nb1 cairo-gobject-1.16.0nb4 readline-8.0 json-glib-1.4.4nb1
consolekit-1.2.1nb4 nghttp2-1.41.0 libidn2-2.3.0 libuv-1.38.1 curl-7.71.1 py37-docutils-0.16 m4-1.4.18nb2 web2c-2020nb1
poppler-glib-0.87.0 libgxps-0.2.2nb23 djvulibre-lib-3.5.27 wayland-protocols-1.20 startup-notification-0.12nb3 dconf-0.36.0
py27-gtk2-2.24.0nb33 libdbusmenu-gtk3-12.10.2nb18 zenity-2.32.1nb29 libsoup-2.70.0nb2 libdbusmenu-glib-12.10.2nb9 libIDL-0.8.14nb5
glib-networking-2.64.3

78 packages to upgrade:
xmlto-0.0.28nb3 vala-0.48.7 tk-8.6.10 tiff-4.1.0 tcl-8.6.10nb2 rhash-1.4.0 rarian-0.8.1nb5 python37-3.7.8nb1 py37-six-1.15.0
py37-setuptools-44.1.1 py37-roman-3.3 py37-lxml-4.5.2 py37-libxml2-2.9.10nb1 py37-gobject3-3.36.1 py37-expat-3.7.8
py37-cElementTree-3.7.8 py27-setuptools-44.1.1 py27-gobject3-3.36.1 png-1.6.37 pcre2-10.35nb1 openjpeg-2.3.1nb3 nspr-4.27
ninja-build-1.10.0nb1 netpbm-10.79.04nb4 mpfr-4.0.2nb1 mozilla-rootcerts-1.0.20200529nb1 meson-0.55.0nb2 mate-screensaver-1.24.0nb1
mate-power-manager-1.24.1 mate-media-1.24.0nb1 mate-control-center-1.24.0nb1 mate-common-1.24.1 mate-calc-1.24.0nb1
mate-backgrounds-1.24.1 libwebp-1.1.0nb1 libspectre-0.2.9 libsecret-0.20.3 libpsl-0.21.1 libmatemixer-1.24.0nb1 libidn-1.36
libgpg-error-1.38 libgcrypt-1.8.6 libcups-2.3.3nb4 libappindicator-12.10.0nb5 lcms2-2.11 jpeg-9d jbigkit-2.1nb1 jbig2dec-0.18
hunspell-1.7.0nb2 help2man-1.47.16 harfbuzz-2.7.1 gssdp-1.0.3nb9 gnutls-3.6.14 gmp-6.2.0 glib2-tools-2.64.4 glib2-2.64.4
ghostscript-agpl-9.52nb2 ghostscript-9.05nb22 gettext-tools-0.21nb1 gettext-lib-0.21 gdbus-codegen-2.64.4 fribidi-1.0.10
exempi-2.5.0nb4 eom-1.24.0nb1 docbook-xsl-1.79.2nb3 dbus-1.12.20 cmake-3.18.1 caja-extensions-1.24.0nb2 caja-1.24.0nb1
boost-headers-1.73.0nb1 bison-3.4.2 bash-5.0.18 automake-1.16.2 atk-2.36.0 at-spi2-core-2.36.0 at-spi2-atk-2.34.2
osabi-NetBSD-9.99.69 gupnp-1.0.3nb7

1 package to install:
sqlite3-3.32.3

156 to refresh, 78 to upgrade, 1 to install
0B to download, 8014K to install

proceed ? [Y/n] y
refreshing xorg-util-macros-1.19.2...
Memory fault (core dumped)

$ gdb /usr/pkg/bin/pkgin ./pkgin.core
[...]
[New process 2371]
Core was generated by `pkgin'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 __flockfile_internal (internal=1, fp=0x0) at /home/source/ab/HEAD/src/lib/libc/stdio/flockfile.c:103
103 /home/source/ab/HEAD/src/lib/libc/stdio/flockfile.c: No such file or directory.
(gdb) bt
#0 __flockfile_internal (internal=1, fp=0x0) at /home/source/ab/HEAD/src/lib/libc/stdio/flockfile.c:103
#1 __flockfile_internal (fp=fp@entry=0x0, internal=internal@entry=1) at /home/source/ab/HEAD/src/lib/libc/stdio/flockfile.c:97
#2 0x00007774fd1657b3 in vfprintf (fp=0x0, fmt0=0x41a0b0 "---%s: %s", ap=ap@entry=0x7f7fff7f8748)
at /home/source/ab/HEAD/src/lib/libc/stdio/vfwprintf.c:554
#3 0x00007774fd15fb39 in fprintf (fp=, fmt=) at /home/source/ab/HEAD/src/lib/libc/stdio/fprintf.c:57
#4 0x0000000000404a1c in log_tag (fmt=0x41a18c "refreshing %s...\n") at actions.c:207
#5 0x0000000000404dc6 in do_pkg_install (installhead=0x7774fe9fe0c8) at actions.c:330
#6 0x0000000000405b98 in pkgin_install (opkgargs=0x7774fe12e000, do_inst=1, upgrade=1) at actions.c:672
#7 0x00000000004062ae in pkgin_upgrade (do_inst=1) at actions.c:901
#8 0x000000000040944f in main (argc=2, argv=0x7f7fff7fa048) at main.c:224

[jperkin]

Thanks! Will look at this today.

FWIW there's no such thing as pkgin upgrade <package>, there's only the singular pkgin upgrade command to upgrade every package.

[jperkin]

It's also worth mentioning that, as described in #102, the -V flag actually does the complete opposite of what you expect!

[dhgutteridge]

It's also worth mentioning that, as described in #102, the -V flag actually does the complete opposite of what you expect!

Yeah, once I actually used it, and looked at what it was doing, I was puzzled, because it wasn't what I thought I'd get. That was my first time really using pkgin for anything, so I wanted as much detail as possible about what it was doing. Anyway, good you've opened #102, thanks!