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
Seems to be fixed in patchlevel releases.