Nullpointer dereference when freeing message media after fetching complete history

[majn]

How to reproduce

1. Call tgl_do_get_difference and set the flag to sync from start.
2. Load every single received message photo
3. Call tgl_free_all()

This will cause a nullpointer dereference in libtgl:

    (lldb) bt
    thread #1: tid = 0x440cf0, 0x000000010e127dbb telegram-adium`tgls_free_photo(TLS=0x0000000102804200, P=0x0000000000000000) + 27 at structures.c:1702, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x10)
    frame #0: 0x000000010e127dbb telegram-adium`tgls_free_photo(TLS=0x0000000102804200, P=0x0000000000000000) + 27 at structures.c:1702
    frame #1: 0x000000010e1283be telegram-adium`tgls_free_message_media(TLS=<unavailable>, M=0x0000608001530e64) + 78 at structures.c:1757
    frame #2: 0x000000010e12889d telegram-adium`tgls_free_message [inlined] tgls_clear_message(M=<unavailable>) + 77 at structures.c:1841
    frame #3: 0x000000010e128860 telegram-adium`tgls_free_message(TLS=<unavailable>, M=0x0000608001530e00) + 16 at structures.c:1858
    frame #4: 0x000000010e129428 telegram-adium`tree_act_ex_message(T=0x0000608001035040, act=0x000000010e129e30, extra=0x0000000102804200) + 56 at structures.c:85
    frame #5: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x00006080010350c0, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #6: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x0000608001035120, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #7: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x0000608001035260, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #8: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x00006080010354e0, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #9: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x00006080010355c0, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #10: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x000060800043be00, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #11: 0x000000010e12941e telegram-adium`tree_act_ex_message(T=0x0000608001239a80, act=0x000000010e129e30, extra=0x0000000102804200) + 46 at structures.c:85
    frame #12: 0x000000010e129ebe telegram-adium`tgl_free_all(TLS=0x0000000102804200) + 110 at structures.c:2202
    frame #13: 0x000000010e10a53e telegram-adium`connection_data_free(conn=0x00006080002c02a0) + 222 at tgp-structs.c:118
    frame #14: 0x000000010e0ee303 telegram-adium`tgprpl_close(gc=0x00006080002a0f00) + 51 at telegram-purple.c:609
    frame #15: 0x00000001007fbda6 libpurple`_purple_connection_destroy + 240
    frame #16: 0x00000001007e9cb2 libpurple`purple_account_disconnect + 168
    frame #17: 0x000000010041bee4 AdiumLibpurple`-[CBPurpleAccount disconnect] + 146
    frame #18: 0x000000010041c777 AdiumLibpurple`-[CBPurpleAccount updateStatusForKey:] + 50
    frame #19: 0x000000010041eefe AdiumLibpurple`-[CBPurpleAccount preferencesChangedForGroup:key:object:preferenceDict:firstTime:] + 94
    frame #20: 0x00000001000f3d00 Adium`___lldb_unnamed_function3759$$Adium + 394
    frame #21: 0x000000010011993d Adium`___lldb_unnamed_function4361$$Adium + 308
    frame #22: 0x00000001004db187 Adium`-[AIAccount(Abstract) setShouldBeOnline:] + 70
    frame #23: 0x00000001000ecda8 Adium`___lldb_unnamed_function3671$$Adium + 706
    frame #24: 0x00007fff8df6a7bc CoreFoundation`__invoking___ + 140
    frame #25: 0x00007fff8df6a612 CoreFoundation`-[NSInvocation invoke] + 290
    frame #26: 0x00007fff8e00a5c6 CoreFoundation`-[NSInvocation invokeWithTarget:] + 54
    frame #27: 0x00007fff983d04eb Foundation`__NSFireDelayedPerform + 364
    frame #28: 0x00007fff8dfe62e4 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
    frame #29: 0x00007fff8dfe5f73 CoreFoundation`__CFRunLoopDoTimer + 1059
    frame #30: 0x00007fff8e05953d CoreFoundation`__CFRunLoopDoTimers + 301
    frame #31: 0x00007fff8dfa1608 CoreFoundation`__CFRunLoopRun + 2024
    frame #32: 0x00007fff8dfa0bd8 CoreFoundation`CFRunLoopRunSpecific + 296
    frame #33: 0x00007fff8a7aa56f HIToolbox`RunCurrentEventLoopInMode + 235
    frame #34: 0x00007fff8a7aa1ee HIToolbox`ReceiveNextEventCommon + 179
    frame #35: 0x00007fff8a7aa12b HIToolbox`_BlockUntilNextEventMatchingListInModeWithFilter + 71
    frame #36: 0x00007fff8c9048ab AppKit`_DPSNextEvent + 978
    frame #37: 0x00007fff8c903e58 AppKit`-[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 346
    frame #38: 0x00007fff8c8f9af3 AppKit`-[NSApplication run] + 594
    frame #39: 0x00007fff8c876244 AppKit`NSApplicationMain + 1832
    frame #40: 0x0000000100002584 Adium`___lldb_unnamed_function1$$Adium + 52

Using libtgl in my project on commit https://github.com/majn/telegram-purple/commit/1004a4005d04e6bf41c255fc2fc54a07ede1b006 , the libtgl version is my own modified branch including my recent pull request https://github.com/majn/tgl/commit/126b42c6d281841acc541735e845d94c54298f46 , although the changes don't seem to affect this issues.

[majn]

Fix is pushed on master

[majn]

Sorry, its only fixed in telegram-purple, I didn't notice that this issue was on a different repository. :P