Correct line numbers in stacktrace

issues/templates/issues/issue_stacktrace.html

@@ -1,6 +1,7 @@
 {% extends "issues/base.html" %}
 {% load static %}
 {% load stricter_templates %}
+{% load issues %}
 
 {% block tab_content %}
 {# <div class="font-bold">Stacktrace:</div> I think this is obvious?#}
@@ -47,7 +48,7 @@
                 <div class="pl-6 pr-6 pt-8 {% if not forloop.last %}border-b-2{% endif %}">{# convience div for padding & border; the border is basically the top-border of the next header #}
                     <div class="bg-slate-50">{# code listing #}
                         {# the spread-out pX-6 in this code is intentional to ensure the padding is visible when scrolling to the right, and not visible when scrolling is possible (i.e. the text is cut-off awkwardly to hint at scrolling #}
-                        <ol class="list-decimal overflow-x-auto list-inside pt-6 pb-6" start="100">
+                        <ol class="list-decimal overflow-x-auto list-inside pt-6 pb-6" start="{{ frame|firstlineno }}">
                         {% for line in frame.pre_context %}<li class="pl-6"><div class="whitespace-pre w-full inline pr-6">{{ line }} {# leave space to avoid collapse #}</div></li>{% endfor %}
                         {# the gradient is a workaround, because I can't get a full-width elem going here inside the overflow #}
                         {# when some other line is overflowing. Using the gradient hides this fact (it happens to also look good) #}

theme/templatetags/issues.py

@@ -0,0 +1,7 @@
+from django import template
+register = template.Library()
+
+
+@register.filter(name='firstlineno')
+def firstlineno(value):
+    return value['lineno'] - len(value['pre_context'])