SIGFPE if dps_plot_points < 6

[0xjc]

Describe the bug

SIGFPE in print_html_player_plots if using dps_plot_stat with dps_plot_points < 6.

Expected behavior

No crash

To Reproduce

Add to any sim with html report

dps_plot_stat=crit
dps_plot_step=1000
dps_plot_points=5
dps_plot_iterations=1000

Additional information

• SimulationCraft Version (required)
  trunk (b9cf995)

Stack trace:

Thread 1 "simc" received signal SIGFPE, Arithmetic exception.
0x0000555557893ac5 in (anonymous namespace)::print_html_player_plots (os=..., p=...) at /home/ubuntu/wow/simc/engine/report/report_html_player.cpp:3254
3254            if ( idx % rows == 0 )
(gdb) p rows
$1 = 0
(gdb) bt
#0  0x0000555557893ac5 in (anonymous namespace)::print_html_player_plots (os=..., p=...) at /home/ubuntu/wow/simc/engine/report/report_html_player.cpp:3254
#1  0x00005555578b198c in (anonymous namespace)::print_html_player_ (p=..., os=...) at /home/ubuntu/wow/simc/engine/report/report_html_player.cpp:4954
#2  report::print_html_player (os=..., p=...) at /home/ubuntu/wow/simc/engine/report/report_html_player.cpp:5029
#3  0x000055555787c8b1 in (anonymous namespace)::print_html_ (sim=..., os=...) at /home/ubuntu/wow/simc/engine/report/report_html_sim.cpp:1236
#4  report::print_html (sim=...) at /home/ubuntu/wow/simc/engine/report/report_html_sim.cpp:1360
#5  0x0000555557726960 in report::print_suite (sim=sim@entry=0x7fffffffc710) at /home/ubuntu/wow/simc/engine/report/reports.cpp:259
#6  0x0000555556f2cafd in sim_t::main (this=this@entry=0x7fffffffc710, args=std::vector of length 1, capacity 1 = {...}) at /home/ubuntu/wow/simc/engine/sc_main.cpp:368
#7  0x0000555556f2cca7 in main (argc=2, argv=0x7fffffffdf28) at /home/ubuntu/wow/simc/engine/sc_main.cpp:408

[renanthera]

I'm struggling to replicate this either on head or on the commit you indicated. Can you provide some additional context such as what build system and compiler you were using?

[0xjc]

CMake, Ninja, Linux x86-64, gcc 13.3.0

Also repros on Raidbots: https://www.raidbots.com/simbot/report/48mXG2ywAe3S4fbuxDgR3P

Here's a specific string:

html=report.html

single_actor_batch=1
target_error=
iterations=1000

report_details=1

dps_plot_stat=crit
dps_plot_step=100
dps_plot_points=5
dps_plot_iterations=100

# Hft - Destruction - 2026-03-28 23:03 - US/Mal'Ganis
# SimC Addon 12.0.1-02
# WoW 12.0.1.66709, TOC 120001
# Requires SimulationCraft 1000-01 or newer

warlock="Hft"
level=90
race=dwarf
region=us
server=malganis
role=spell
professions=alchemy=30/inscription=100
spec=destruction
# loot_spec=destruction

talents=CsQAy0jxIDofkwJmoH7WhvESoxMmZmpZZMMzMzsNLjxMLGz2iHYAAwMzYmZWsADMLGNmBwsFbMAAwYA2AAmZgZGjBAAgZmZAAYmhB


# Abyssal Immolator's Smoldering Flames (279)
head=,id=250042,enchant_id=8017,bonus_id=12803/13335/13338/6652/12667/13575
# Eternal Voidsong Chain (276)
neck=,id=249368,gem_id=240890,bonus_id=6652/13668/13334/12798
# Abyssal Immolator's Fury (263)
shoulder=,id=250040,enchant_id=8001,bonus_id=13333/13340/6652/13574/12790
# Fluxweave Cloak (266)
back=,id=251206,bonus_id=12795/13440/6652/13577/12699
# Abyssal Immolator's Dreadrobe (276)
chest=,id=250045,enchant_id=7987,bonus_id=13334/13336/6652/13575/12798
# Thalassian Competitor's Cloth Bands (246)
wrist=,id=239677,gem_id=240983,bonus_id=12245/13576/12497/13571/13448/8960/12384/8790,crafted_stats=36/40,crafting_quality=5
# Sprawling Tendrils (266)
hands=,id=249631,bonus_id=6652/13577/12795
# Infernal Greatlock Girdle (266)
waist=,id=260371,gem_id=240890,bonus_id=6652/13534/13577/13334/12795/10844,crafted_stats=49/40
# Abyssal Immolator's Pillars (276)
legs=,id=250041,enchant_id=7935,bonus_id=13334/13339/6652/13575/12798
# Slippers of the Midnight Flame (266)
feet=,id=249305,enchant_id=7963,bonus_id=6652/13577/13334/12795
# Omission of Light (276)
finger1=,id=251093,enchant_id=7967,gem_id=240908,bonus_id=13440/6652/13668/12699/12798
# Occlusion of Void (276)
finger2=,id=251217,enchant_id=7967,gem_id=240908,bonus_id=13440/6652/13668/12699/12798
# Locus-Walker's Ribbon (269)
trinket1=,id=249809,bonus_id=6652/13334/12796
# Vaelgor's Final Stare (266)
trinket2=,id=249346,bonus_id=6652/13334/12795
# Aln'hara Cane (285)
main_hand=,id=245770,enchant_id=8039,bonus_id=12214/12497/12066/12693/8960/8791/13622/13667,crafted_stats=40/36,crafting_quality=5

[renanthera]

I can't repro on recent versions of clang nor gcc, and don't want to deal with compiler faff. Perhaps someone already has a version of gcc that can reproduce the behaviour and correct it.

Presumably the smallest expected value for rows is 1, but clearly something horrible is occurring and that ends out not being the case.