remove format parms from back_to

app/helpers/talks_helper.rb

@@ -1,2 +1,10 @@
 module TalksHelper
+  def normalize_back_to(back_to)
+    return nil if back_to.blank?
+
+    uri = URI.parse(back_to)
+    params = Rack::Utils.parse_query(uri.query.to_s).except("infinite_count", "format", "page")
+    uri.query = params.present? ? params.to_query : nil
+    uri.to_s
+  end
 end

app/views/talks/_card.html.erb

@@ -3,7 +3,7 @@
 <% language = Language.by_code(talk.language) %>
 
 <div class="card card-compact bg-white border w-full" id="<%= dom_id talk %>">
-  <%= link_to talk_path(talk, back_to: back_to, back_to_title: back_to_title), class: "flex aspect-video overflow-hidden relative group", data: {action: "mouseover->preserve-scroll#updateLinkBackToWithScrollPosition"} do %>
+  <%= link_to talk_path(talk, back_to: normalize_back_to(back_to), back_to_title: back_to_title), class: "flex aspect-video overflow-hidden relative group", data: {action: "mouseover->preserve-scroll#updateLinkBackToWithScrollPosition"} do %>
     <% if language && language != "English" %>
       <div class="absolute top-0 left-0 z-20 m-3 p-1 px-2 bg-black/15 backdrop-blur-md rounded-full">
         <span><%= language_to_emoji(language) %></span>
@@ -62,7 +62,7 @@
   <div class="card-body flex flex-row justify-between items-start gap-2">
     <div class="flex flex-col items-start h-full justify-between gap-2 w-full">
       <div class="flex items-start justify-between gap-2 w-full">
-        <%= link_to talk_path(talk, back_to: back_to, back_to_title: back_to_title), data: {action: "mouseover->preserve-scroll#updateLinkBackToWithScrollPosition"} do %>
+        <%= link_to talk_path(talk, back_to: normalize_back_to(back_to), back_to_title: back_to_title), data: {action: "mouseover->preserve-scroll#updateLinkBackToWithScrollPosition"} do %>
           <%= content_tag :h2, class: "text-sm font-sans font-medium" do %>
             <%= sanitize(talk.title_with_snippet, tags: ["mark"]) %>
           <% end %>

test/helpers/talks_helper_test.rb

@@ -0,0 +1,21 @@
+require "test_helper"
+
+class TalksHelperTest < ActionView::TestCase
+  test "normalize_back_to removes infinite_count and format params" do
+    assert_equal "talks_url?s=rails", normalize_back_to("talks_url?s=rails")
+    assert_equal "talks_url?s=rails", normalize_back_to("talks_url?s=rails&infinite_count=1")
+    assert_equal "talks_url?s=rails", normalize_back_to("talks_url?s=rails&format=turbo_stream")
+    assert_equal "talks_url", normalize_back_to("talks_url?format=turbo_stream&page=2")
+    assert_equal "talks_url?s=rails", normalize_back_to("talks_url?s=rails&infinite_count=1&format=turbo_stream")
+    assert_equal "talks_url?s=rails", normalize_back_to("talks_url?s=rails&infinite_count=111&format=turbo_stream")
+  end
+
+  test "normalize_back_to handles empty params" do
+    assert_equal "talks_url", normalize_back_to("talks_url")
+  end
+
+  test "normalize_back_to preserves other params" do
+    result = normalize_back_to("talks_url?topic=ruby&speaker=john&infinite_count=1")
+    assert_equal ["speaker=john", "topic=ruby"].sort, URI.parse(result).query.split("&").sort
+  end
+end