Prevent Chrome from crashing on large function lists. (#858)

---------
Co-authored-by: Tyler Mace <macetw@lat.ai>
Co-authored-by: Spacetown <40258682+spacetown@users.noreply.github.com>

CHANGELOG.rst

@@ -39,8 +39,8 @@ New features and notable changes:
 - Use different color for partial covered lines in HTML report. (:issue:`839`)
 - Add support to generate LCOV info files. (:issue:`830`)
 - Add support for FIPS enabled OS when used with Python 3.9. (:issue:`850`)
-- Reduce file size for detailed HTML reports by using CSS to link the function lists. (:issue:`840`)
 - Ignore all negative hits if :option:`--gcov-ignore-parse-errors` is used. (:issue:`852`)
+- Reduce file size for detailed HTML reports by merging columns the function lists. (:issue:`840`)
 - Use literal options for sorting and TXT metric. (:issue:`867`)
 
   - The :option:`-b`, :option:`--txt-branches` and :option:`--branches` are deprecated, use :option:`--txt-metric` instead.
@@ -49,6 +49,7 @@ New features and notable changes:
   - The :option:`--sort-uncovered` and :option:`--sort-percentage` are deprecated, use :option:`--sort` instead.
     The reason for this is that only one sorting order shall be selectable and and an enumeration is easier to handle
     than several flags.
+- Split list of functions into tables with maximum 10000 rows to fix rendering issues. (:issue:`858`)
 
 - The development branch is renamed from ``master`` to ``main``. (:issue:`829`, :issue:`873`)
 - Add support for decision coverage metric in text report (:issue:`864`)

gcovr/formats/html/default/functions_page.content.html

@@ -1,11 +1,12 @@
 {# -*- engine: jinja -*- #}
+{% for function_batch in all_functions | batch(10000) %}
 <table class="listOfFunctions">
   <tr>
     <th>Function (File:Line)</th>
     <th>Call count</th>
     <th>Block coverage</th>
   </tr>
-{% for entry in all_functions %}
+  {% for entry in function_batch %}
   <tr>
     {#- #}<td><a href="{{ entry['html_filename'] }}#l{{ entry['line'] }}">{{ entry["name"] }} ({{ entry["filename"] }}:{{ entry["line"] }})</a></td>
     {#- #}<td>
@@ -19,5 +20,6 @@
     {#- #}<td>{{ entry["blocks"] }}%</td>
     {#- -#}
   </tr>
-{% endfor %}
+  {% endfor %}
 </table>
+{% endfor %}

gcovr/formats/html/github/functions_page.content.html

@@ -1,11 +1,12 @@
 {# -*- engine: jinja -*- #}
+{% for function_batch in all_functions | batch(10000) %}
 <table class="m-3 text-mono text-small listOfFunctions" style="width:100%;">
-   <tr class="text-left">
-      <th>Function (File:Line)</th>
-      <th>Call count</th>
-      <th>Block coverage</th>
+  <tr class="text-left">
+    <th>Function (File:Line)</th>
+    <th>Call count</th>
+    <th>Block coverage</th>
   </tr>
-{% for entry in all_functions %}
+  {% for entry in function_batch %}
   <tr>
     {#- #}<td><a href="{{ entry['html_filename'] }}#l{{ entry['line'] }}">{{ entry["name"] }} ({{ entry["filename"] }}:{{ entry["line"] }})</a></td>
     {#- #}<td>
@@ -19,5 +20,6 @@
     {#- #}<td>{{ entry["blocks"] }}%</td>
     {#- -#}
   </tr>
-{% endfor %}
+  {% endfor %}
 </table>
+{% endfor %}