AK+Everywhere: Make UTF-8 and UTF-32 to UTF-16 converters fallible

These could fail to allocate the underlying storage needed to store the
UTF-16 data. Propagate these errors.

1 files changed, 14 insertions, 12 deletions

diff --git a/AK/Utf16View.cpp b/AK/Utf16View.cpp
index 1dc0b55d4b..4c23484bee 100644
--- a/AK/Utf16View.cpp
+++ b/AK/Utf16View.cpp
@@ -5,6 +5,7 @@
  */
 
 #include <AK/CharacterTypes.h>
+#include <AK/Concepts.h>
 #include <AK/StringBuilder.h>
 #include <AK/StringView.h>
 #include <AK/Utf16View.h>
@@ -20,45 +21,46 @@ static constexpr u16 low_surrogate_max = 0xdfff;
 static constexpr u32 replacement_code_point = 0xfffd;
 static constexpr u32 first_supplementary_plane_code_point = 0x10000;
 
-template<typename UtfViewType>
-static Utf16Data to_utf16_impl(UtfViewType const& view)
-requires(IsSame<UtfViewType, Utf8View> || IsSame<UtfViewType, Utf32View>)
+template<OneOf<Utf8View, Utf32View> UtfViewType>
+static ErrorOr<Utf16Data> to_utf16_impl(UtfViewType const& view)
 {
     Utf16Data utf16_data;
-    utf16_data.ensure_capacity(view.length());
+    TRY(utf16_data.try_ensure_capacity(view.length()));
 
     for (auto code_point : view)
-        code_point_to_utf16(utf16_data, code_point);
+        TRY(code_point_to_utf16(utf16_data, code_point));
 
     return utf16_data;
 }
 
-Utf16Data utf8_to_utf16(StringView utf8_view)
+ErrorOr<Utf16Data> utf8_to_utf16(StringView utf8_view)
 {
     return to_utf16_impl(Utf8View { utf8_view });
 }
 
-Utf16Data utf8_to_utf16(Utf8View const& utf8_view)
+ErrorOr<Utf16Data> utf8_to_utf16(Utf8View const& utf8_view)
 {
     return to_utf16_impl(utf8_view);
 }
 
-Utf16Data utf32_to_utf16(Utf32View const& utf32_view)
+ErrorOr<Utf16Data> utf32_to_utf16(Utf32View const& utf32_view)
 {
     return to_utf16_impl(utf32_view);
 }
 
-void code_point_to_utf16(Utf16Data& string, u32 code_point)
+ErrorOr<void> code_point_to_utf16(Utf16Data& string, u32 code_point)
 {
     VERIFY(is_unicode(code_point));
 
     if (code_point < first_supplementary_plane_code_point) {
-        string.append(static_cast<u16>(code_point));
+        TRY(string.try_append(static_cast<u16>(code_point)));
     } else {
         code_point -= first_supplementary_plane_code_point;
-        string.append(static_cast<u16>(high_surrogate_min | (code_point >> 10)));
-        string.append(static_cast<u16>(low_surrogate_min | (code_point & 0x3ff)));
+        TRY(string.try_append(static_cast<u16>(high_surrogate_min | (code_point >> 10))));
+        TRY(string.try_append(static_cast<u16>(low_surrogate_min | (code_point & 0x3ff))));
     }
+
+    return {};
 }
 
 bool Utf16View::is_high_surrogate(u16 code_unit)