AK: Replace the mutable String::replace API with an immutable version

This removes the awkward String::replace API which was the only String
API which mutated the String and replaces it with a new immutable
version that returns a new String with the replacements applied. This
also fixes a couple of UAFs that were caused by the use of this API.

As an optimization an equivalent StringView::replace API was also added
to remove an unnecessary String allocations in the format of:
`String { view }.replace(...);`

1 files changed, 2 insertions, 5 deletions

diff --git a/Userland/Applications/Browser/Tab.cpp b/Userland/Applications/Browser/Tab.cpp
index 0482b3a783..f043adb032 100644
--- a/Userland/Applications/Browser/Tab.cpp
+++ b/Userland/Applications/Browser/Tab.cpp
@@ -40,11 +40,8 @@ namespace Browser {
 
 URL url_from_user_input(const String& input)
 {
-    if (input.starts_with("?") && !g_search_engine.is_null()) {
-        auto url = g_search_engine;
-        url.replace("{}", URL::percent_encode(input.substring_view(1)));
-        return URL(url);
-    }
+    if (input.starts_with("?") && !g_search_engine.is_null())
+        return URL(g_search_engine.replace("{}", URL::percent_encode(input.substring_view(1))));
 
     auto url = URL(input);
     if (url.is_valid())