vterm sometimes crashes

[Maurizio Lombardi]

Sometimes vterm crashes when playing with command history and command completion.
I didn't find a reliable way to reproduce it yet but I have a stack trace:

app/vterm(59) Assertion failed (scrbuf→row < scrbuf→rows) in task 59, file "generic/io/chargrid.c", line 145.
app/vterm(59) 0x0000000000ad3d80: 0x0000000000416665()
app/vterm(59) 0x0000000000ad3db0: 0x0000000000416828()
app/vterm(59) 0x0000000000ad3dd0: 0x0000000000409736()
app/vterm(59) 0x0000000000ad3e30: 0x00000000004013f4()
app/vterm(59) 0x0000000000ad3f40: 0x000000000040d006()
app/vterm(59) 0x0000000000ad3fd0: 0x0000000000413d80()
app/vterm(59) 0x0000000000ad3ff0: 0x00000000004115b9()
app/vterm(59) — end of stack trace —
srv/taskmon(16) taskmon: Task 59 fault in thread 0xffffffff84d293d0.
srv/taskmon(16) taskmon: Executing /app/taskdump -t 59
app/taskdump(71) Task Dump Utility
app/taskdump(71) Dumping task '/app/vterm' (task ID 59).
app/taskdump(71) Loaded symbol table from /app/vterm
app/taskdump(71) Threads:
app/taskdump(71) [1] hash: 0xffffffff84d293d0
app/taskdump(71) Thread 0xffffffff84d293d0: PC = 0x000000000040fe13 (_ready_list_pop.constprop.15+339). FP = 0x000000000064dfa0
app/taskdump(71) 0x000000000064dfa0: 0x000000000040fe13 (_ready_list_pop.constprop.15+339)
app/taskdump(71) 0x000000000064dfd0: 0x000000000041158e (_helper_fibril_fn+62)
app/taskdump(71) 0x000000000064dff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Address space areas:
app/taskdump(71) [1] flags: R-XC base: 0x0000000000400000 size: 122880
app/taskdump(71) [2] flags: RW-C base: 0x000000000061d000 size: 172032
app/taskdump(71) [3] flags: RW-C base: 0x0000000000647000 size: 4096
app/taskdump(71) [4] flags: RW-C base: 0x0000000000649000 size: 4096
app/taskdump(71) [5] flags: RW-C base: 0x000000000064b000 size: 4096
app/taskdump(71) [6] flags: RW-C base: 0x000000000064d000 size: 4096
app/taskdump(71) [7] flags: R—C base: 0x000000000064f000 size: 4096
app/taskdump(71) [8] flags: RW-C base: 0x0000000000650000 size: 159744
app/taskdump(71) [9] flags: RW-C base: 0x0000000000678000 size: 1048576
app/taskdump(71) [10] flags: RW-C base: 0x0000000000779000 size: 1048576
app/taskdump(71) [11] flags: RW-C base: 0x000000000087a000 size: 1318912
app/taskdump(71) [12] flags: RW-C base: 0x00000000009bc000 size: 94208
app/taskdump(71) [13] flags: RW-C base: 0x00000000009d4000 size: 1048576
app/taskdump(71) [14] flags: RW-C base: 0x0000000000ad5000 size: 1048576
app/taskdump(71) [15] flags: RW-C base: 0x0000000000bd6000 size: 1048576
app/taskdump(71) [16] flags: R-XC base: 0x0000000070000000 size: 86016
app/taskdump(71) [17] flags: RW-C base: 0x0000000070215000 size: 126976
app/taskdump(71) [18] flags: RW-C base: 0x0000000070234000 size: 4096
app/taskdump(71) [19] flags: RW-C base: 0x0000000070235000 size: 4096
app/taskdump(71) [20] flags: RW-C base: 0x0000000070237000 size: 4096
app/taskdump(71) [21] flags: RW-C base: 0x0000000070239000 size: 4096
app/taskdump(71) [22] flags: RW-C base: 0x000000007023b000 size: 4096
app/taskdump(71) [23] flags: R—C base: 0x000000007023d000 size: 4096
app/taskdump(71) [24] flags: RW-C base: 0x000000007023e000 size: 4096
app/taskdump(71) [25] flags: RW-C base: 0x0000000070240000 size: 1048576
app/taskdump(71) [26] flags: RW-C base: 0x00007ffffff00000 size: 1048576
app/taskdump(71) Fibril 0x00000000006293e0:
app/taskdump(71) 0x000000007033fc90: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x000000007033fcc0: 0x0000000000410543 (_fibril_switch_to+227)
app/taskdump(71) 0x000000007033fd80: 0x0000000000410b60 (fibril_wait_timeout+560)
app/taskdump(71) 0x000000007033fda0: 0x0000000000414549 (async_manager+25)
app/taskdump(71) 0x000000007033fdc0: 0x000000000040022c (_start+0)
app/taskdump(71) 0x000000007033fdf0: 0x0000000000405ef9 (libc_main+393)
app/taskdump(71) 0x000000007033fe10: 0x00000000004002d3 (c_start+147)
app/taskdump(71) 0x000000007033fe20: 0x0000000000400238 (_start+12)
app/taskdump(71) Fibril 0x0000000000647c30:
app/taskdump(71) 0x0000000000649df0: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x0000000000649e20: 0x0000000000410543 (_fibril_switch_to+227)
app/taskdump(71) 0x0000000000649ee0: 0x0000000000410b60 (fibril_wait_timeout+560)
app/taskdump(71) 0x0000000000649f30: 0x00000000004117d5 (fibril_ipc_wait+197)
app/taskdump(71) 0x0000000000649fd0: 0x00000000004139ab (async_manager_fibril+27)
app/taskdump(71) 0x0000000000649ff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Fibril 0x000000000064b870:
app/taskdump(71) 0x000000000064df80: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x000000000064dfa0: 0x00000000004102ab (_fibril_switch_to.constprop.17+187)
app/taskdump(71) 0x000000000064dfd0: 0x000000000041158e (_helper_fibril_fn+62)
app/taskdump(71) 0x000000000064dff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Fibril 0x000000000066c410:
app/taskdump(71) 0x0000000000777d70: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x0000000000777da0: 0x0000000000410543 (_fibril_switch_to+227)
app/taskdump(71) 0x0000000000777e60: 0x0000000000410b60 (fibril_wait_timeout+560)
app/taskdump(71) 0x0000000000777ed0: 0x0000000000411d79 (fibril_condvar_wait_timeout.constprop.8+201)
app/taskdump(71) 0x0000000000777f00: 0x00000000004154b3 (prodcons_consume+51)
app/taskdump(71) 0x0000000000777fd0: 0x0000000000402448 (event_loop+56)
app/taskdump(71) 0x0000000000777ff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Fibril 0x000000000066c5d0:
app/taskdump(71) 0x0000000000878d60: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x0000000000878d90: 0x0000000000410543 (_fibril_switch_to+227)
app/taskdump(71) 0x0000000000878e50: 0x0000000000410b60 (fibril_wait_timeout+560)
app/taskdump(71) 0x0000000000878ef0: 0x000000000041378f (async_data_read_start+127)
app/taskdump(71) 0x0000000000878fa0: 0x000000000040d24b (win_get_event+75)
app/taskdump(71) 0x0000000000878fd0: 0x0000000000401e65 (fetch_input+37)
app/taskdump(71) 0x0000000000878ff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Fibril 0x000000000066d760:
app/taskdump(71) 0x0000000000ad3c40: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x0000000000ad3d40: 0x000000000040a03e (kio_printf+190)
app/taskdump(71) 0x0000000000ad3d80: 0x00000000004166f2 (stacktrace_kio_print+162)
app/taskdump(71) 0x0000000000ad3db0: 0x000000000041686b (syscall+0)
app/taskdump(71) 0x0000000000ad3dd0: 0x0000000000409736 (chargrid_putwchar+278)
app/taskdump(71) 0x0000000000ad3e30: 0x00000000004013f4 (term_write+244)
app/taskdump(71) 0x0000000000ad3f40: 0x000000000040d006 (con_conn+966)
app/taskdump(71) 0x0000000000ad3fd0: 0x0000000000413d80 (connection_fibril+128)
app/taskdump(71) 0x0000000000ad3ff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Fibril 0x000000000066dbf0:
app/taskdump(71) 0x0000000000bd4cb0: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x0000000000bd4ce0: 0x0000000000410543 (_fibril_switch_to+227)
app/taskdump(71) 0x0000000000bd4da0: 0x0000000000410b60 (fibril_wait_timeout+560)
app/taskdump(71) 0x0000000000bd4df0: 0x0000000000416d8b (mpsc_receive+43)
app/taskdump(71) 0x0000000000bd4e30: 0x0000000000413f1b (async_get_call_timeout+75)
app/taskdump(71) 0x0000000000bd4f40: 0x000000000040cca9 (con_conn+105)
app/taskdump(71) 0x0000000000bd4fd0: 0x0000000000413d80 (connection_fibril+128)
app/taskdump(71) 0x0000000000bd4ff0: 0x00000000004115b9 (_fibril_main+41)
app/taskdump(71) Fibril 0x000000000066e080:
app/taskdump(71) 0x0000000000cd5cb0: 0x0000000000416911 (context_swap+17)
app/taskdump(71) 0x0000000000cd5ce0: 0x0000000000410543 (_fibril_switch_to+227)
app/taskdump(71) 0x0000000000cd5da0: 0x0000000000410b60 (fibril_wait_timeout+560)
app/taskdump(71) 0x0000000000cd5df0: 0x0000000000416d8b (mpsc_receive+43)
app/taskdump(71) 0x0000000000cd5e30: 0x0000000000413f1b (async_get_call_timeout+75)
app/taskdump(71) 0x0000000000cd5f40: 0x000000000040cca9 (con_conn+105)
app/taskdump(71) 0x0000000000cd5fd0: 0x0000000000413d80 (connection_fibril+128)
app/taskdump(71) 0x0000000000cd5ff0: 0x00000000004115b9 (_fibril_main+41)