NULL pointer passed to as_checksum_set_value from as_cache_file_read

[iainlane]

I was trying to reproduce another bug that I saw (couldn't, might be fixed with 0.10, will keep an eye out), when I made appstreamcli crash like this.

laney@raleigh> sudo env LD_LIBRARY_PATH=/dev/canonical/release/appstream/build/src gdb --args ~/dev/canonical/release/appstream/build/tools/appstreamcli refresh-cache --force 
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Reading symbols from /home/laney/dev/canonical/release/appstream/build/tools/appstreamcli...done.
(gdb) run
Starting program: /home/laney/dev/canonical/release/appstream/build/tools/appstreamcli refresh-cache --force
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

(appstreamcli:18543): GLib-CRITICAL **: the GVariant format string '{us}' has a type of '{us}' but the given value has a type of 'a{sv}'

(appstreamcli:18543): GLib-CRITICAL **: g_variant_get: assertion 'valid_format_string (format_string, TRUE, value)' failed

Program received signal SIGSEGV, Segmentation fault.
strlen () at ../sysdeps/x86_64/strlen.S:106
106 ../sysdeps/x86_64/strlen.S: No such file or directory.
(gdb) bt
#0  0x00007ffff6f5af06 in strlen () at ../sysdeps/x86_64/strlen.S:106
#1  0x00007ffff7b2fb43 in g_strdup (str=0x2 <error: Cannot access memory at address 0x2>) at ././glib/gstrfuncs.c:362
#2  0x00007ffff72c5a34 in as_checksum_set_value (cs=0x63a710 [AsChecksum], value=0x2 <error: Cannot access memory at address 0x2>) at /home/laney/dev/canonical/release/appstream/src/as-checksum.c:165
#3  0x00007ffff72b62f4 in as_cache_file_read (fname=0x62efd0 "/var/cache/app-info/gv/en_GB.gvz", error=0x7fffffffdec8)
    at /home/laney/dev/canonical/release/appstream/src/as-cache-file.c:1094
#4  0x00007ffff72c14cb in as_pool_load_cache_file (pool=0x62c870 [AsPool], fname=0x62efd0 "/var/cache/app-info/gv/en_GB.gvz", error=0x7fffffffdf98) at /home/laney/dev/canonical/release/appstream/src/as-pool.c:751
#5  0x00007ffff72c13c9 in as_pool_load (pool=0x62c870 [AsPool], cancellable=0x0, error=0x7fffffffdf98)
    at /home/laney/dev/canonical/release/appstream/src/as-pool.c:717
#6  0x00007ffff72c21ff in as_pool_refresh_cache (pool=0x62c870 [AsPool], force=1, error=0x7fffffffe000)
    at /home/laney/dev/canonical/release/appstream/src/as-pool.c:1167
#7  0x00000000004058f3 in ascli_refresh_cache (cachepath=0x0, datapath=0x0, forced=1)
    at /home/laney/dev/canonical/release/appstream/tools/ascli-actions-mdata.c:52
#8  0x000000000040435f in as_client_run (argv=0x7fffffffe3d8, argc=2)
    at /home/laney/dev/canonical/release/appstream/tools/appstream-cli.c:213
#9  0x000000000040469e in main (argc=3, argv=0x7fffffffe3d8)
    at /home/laney/dev/canonical/release/appstream/tools/appstream-cli.c:269

...I think it's because you are iterating the wrong dictionary.