#2394 Spurious crashes when unzooming

[Bastian Märkisch]

I experience spurious, occasional crashes when unzooming with the "u" keya log-scale plot with independent y & y2 axis, i.e. not "link"ed. Below are two backtraces, which seem to be related to linked axes, though. Seen with 5.4.1 and 5.5 built with Mingw-w64 and the windows terminal. No MWE yet, because my script(s) are not-so-minimal.

Thread 1 received signal SIGSEGV, Segmentation fault.
map_y_double (value=0) at ../../src/axis.c:2608
2608            if (primary->link_udf->at) {
(gdb) backtrace
#0  map_y_double (value=0) at ../../src/axis.c:2608
#1  0x00000001400096d6 in map_y (value=0) at ../../src/axis.c:2621
#2  0x000000014005f058 in ytick2d_callback (
    this_axis=0x14029c2f0 <axis_array+688>, place=0, text=0x5feb70 "10^{0}",
    ticlevel=0, grid=..., userlabels=0x0) at ../../src/graphics.c:3587
#3  0x0000000140005861 in gen_tics (this=0x14029c2f0 <axis_array+688>,
    callback=0x14005ef4e <ytick2d_callback>) at ../../src/axis.c:1362
#4  0x00000001400069cc in axis_output_tics (axis=FIRST_Y_AXIS,
    ticlabel_position=0x14029e4d4 <ytic_x>, zeroaxis_basis=FIRST_X_AXIS,
    callback=0x14005ef4e <ytick2d_callback>) at ../../src/axis.c:1593
#5  0x000000014005018a in place_grid (layer=-1) at ../../src/graphics.c:224
#6  0x00000001400521c8 in do_plot (plots=0xb615770, pcount=6)
    at ../../src/graphics.c:722
#7  0x000000014009e4fd in eval_plots () at ../../src/plot2d.c:3610
#8  0x0000000140092eee in plotrequest () at ../../src/plot2d.c:286
#9  0x000000014001a0a7 in replotrequest () at ../../src/command.c:2713
#10 0x000000014001567c in do_string_replot (s=0x14022fc10 <NO_KEY+448> "")
    at ../../src/command.c:521
#11 0x0000000140084af5 in apply_zoom (z=0x4b894c0) at ../../src/mouse.c:844
#12 0x0000000140084ee3 in ZoomUnzoom () at ../../src/mouse.c:921
#13 0x00000001400867a8 in builtin_unzoom (ge=0x5ff680)
    at ../../src/mouse.c:1384
#14 0x0000000140086def in event_keypress (ge=0x5ff680, current=true)
    at ../../src/mouse.c:1586
#15 0x000000014008a691 in do_event (ge=0x5ff680) at ../../src/mouse.c:2476
#16 0x0000000140170609 in gp_exec_event (type=3 '\003', mx=13171, my=13719,
    par1=117, par2=0, winid=0) at ../../src/gpexecute.c:240
#17 0x00000001401963c1 in Wnd_exec_event (lpgw=0x4b5cea0, lparam=1441793,
    type=3 '\003', par1=117) at ../../src/win/wgraph.c:4184
#18 0x0000000140197b55 in WndGraphProc (hwnd=0xe0b2c, message=258,
    wParam=117, lParam=1441793) at ../../src/win/wgraph.c:4625

and

Thread 1 received signal SIGSEGV, Segmentation fault.
0x00007ffd397e47af in msvcrt!memmove () from C:\WINDOWS\System32\msvcrt.dll
(gdb) backtrace
#0  0x00007ffd397e47af in msvcrt!memmove ()
   from C:\WINDOWS\System32\msvcrt.dll
#1  0x00000001400089ca in clone_linked_axes (
    axis1=0x14029c2f0 <axis_array+688>, axis2=0xb5d8a00)
    at ../../src/axis.c:2338
#2  0x0000000140084aa1 in apply_zoom (z=0x4ae9460) at ../../src/mouse.c:826
#3  0x0000000140084ee3 in ZoomUnzoom () at ../../src/mouse.c:921
#4  0x00000001400867a8 in builtin_unzoom (ge=0x5ff680)
    at ../../src/mouse.c:1384
#5  0x0000000140086def in event_keypress (ge=0x5ff680, current=true)
    at ../../src/mouse.c:1586
#6  0x000000014008a691 in do_event (ge=0x5ff680) at ../../src/mouse.c:2476
#7  0x0000000140170609 in gp_exec_event (type=3 '\003', mx=22025, my=9601,
    par1=117, par2=0, winid=0) at ../../src/gpexecute.c:240
#8  0x00000001401963c1 in Wnd_exec_event (lpgw=0x4abcea0, lparam=1441793,
    type=3 '\003', par1=117) at ../../src/win/wgraph.c:4184
#9  0x0000000140197b55 in WndGraphProc (hwnd=0x2f0b68, message=258,
    wParam=117, lParam=1441793) at ../../src/win/wgraph.c:462

[Bastian Märkisch]

Seems to be fixed in patchlevel releases.