From 5e5a0a7c4d10c2f629e8b5794360c99447433347 Mon Sep 17 00:00:00 2001
From: patrick96 <p.ziegler96@gmail.com>
Date: Wed, 10 May 2023 16:11:52 +0200
Subject: [PATCH] Make unicode_charlist a vector

---
 include/utils/string.hpp          |  3 +-
 src/utils/string.cpp              | 49 ++++++++++++++++++++-----------
 tests/unit_tests/utils/string.cpp |  7 ++---
 3 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/include/utils/string.hpp b/include/utils/string.hpp
index 62c6ee9d..328ef897 100644
--- a/include/utils/string.hpp
+++ b/include/utils/string.hpp
@@ -1,6 +1,5 @@
 #pragma once
 
-#include <list>
 #include <sstream>
 
 #include "common.hpp"
@@ -56,7 +55,7 @@ struct unicode_character {
    */
   int length{0};
 };
-using unicode_charlist = std::list<unicode_character>;
+using unicode_charlist = std::vector<unicode_character>;
 
 bool contains(const string& haystack, const string& needle);
 bool contains_ignore_case(const string& haystack, const string& needle);
diff --git a/src/utils/string.cpp b/src/utils/string.cpp
index 808a6dc4..a66e00cb 100644
--- a/src/utils/string.cpp
+++ b/src/utils/string.cpp
@@ -272,39 +272,54 @@ static pair<int, uint32_t> utf8_get_len(uint8_t leading) {
 
 /**
  * @brief Create a list of UCS-4 codepoint from a utf-8 encoded string
+ *
+ * If invalid utf8 characters are encountered they are skipped until the next valid codepoint and the function will
+ * eventually return false.
+ *
+ * The result_list is always populated with all valid utf8 codepoints.
+ *
+ * @return Whether the string is completely valid utf8
  */
 bool utf8_to_ucs4(const char* src, unicode_charlist& result_list) {
   assert(src);
+  bool has_errors = false;
   const auto* begin = reinterpret_cast<const uint8_t*>(src);
-  const auto* first = begin;
-  while (*first) {
-    // Number of bytes taken up by this codepoint and the bits contained in the leading byte.
-    auto [len, result] = utf8_get_len(*first);
 
-    // Invalid lengths
+  const auto* current = begin;
+  while (*current) {
+    // Number of bytes taken up by this codepoint and the bits contained in the leading byte.
+    auto [len, result] = utf8_get_len(*current);
+    auto offset = current - begin;
+
+    /*
+     * Invalid lengths, this byte is not a valid leading byte.
+     * Skip it.
+     */
     if (len <= 0 || len > 4) {
-      return false;
+      has_errors = true;
+      current++;
+      continue;
     }
 
-    const uint8_t* next = first + 1;
-    for (; ((*next & UTF8_CONTINUATION_MASK) == UTF8_CONTINUATION_PREFIX) && (next - first < len); next++) {
+    const uint8_t* next = current + 1;
+    for (; ((*next & UTF8_CONTINUATION_MASK) == UTF8_CONTINUATION_PREFIX) && (next - current < len); next++) {
       result = result << 6;
       result |= *next & ~UTF8_CONTINUATION_MASK;
     }
 
-    unicode_character uc_char;
-    uc_char.codepoint = result;
-    uc_char.offset = first - begin;
-    uc_char.length = next - first;
-    result_list.push_back(uc_char);
+    auto actual_len = next - current;
+    current = next;
 
-    if (uc_char.length != len) {
-      return false;
+    if (actual_len != len) {
+      has_errors = true;
+      continue;
     }
 
-    first = next;
+    result_list.push_back(unicode_character{result, static_cast<int>(offset), static_cast<int>(actual_len)});
+    current = next;
   }
-  return true;
+
+  return !has_errors;
 }
 
 /**
diff --git a/tests/unit_tests/utils/string.cpp b/tests/unit_tests/utils/string.cpp
index adfdfd63..e0f1257e 100644
--- a/tests/unit_tests/utils/string.cpp
+++ b/tests/unit_tests/utils/string.cpp
@@ -193,8 +193,8 @@ TEST_P(Utf8ToUCS4AsciiTest, correctness) {
 
   ASSERT_EQ(str.size(), result_list.size());
 
-  int i = 0;
-  for (const auto& unicode_char : result_list) {
+  for (size_t i = 0; i < str.size(); i++) {
+    const auto& unicode_char = result_list[i];
     auto c = str[i];
 
     // Matches the single byte character
@@ -203,8 +203,6 @@ TEST_P(Utf8ToUCS4AsciiTest, correctness) {
     EXPECT_EQ(i, unicode_char.offset);
     // Only takes a single byte
     EXPECT_EQ(1, unicode_char.length);
-
-    i++;
   }
 }
 
@@ -266,5 +264,6 @@ TEST_P(Utf8ToUCS4InvalidTest, correctness) {
   const auto str = GetParam();
   bool success = string_util::utf8_to_ucs4(str.c_str(), result_list);
   EXPECT_FALSE(success);
+  EXPECT_EQ(0, result_list.size());
 }
 // }}}