Utils: Add char append to SmallString

Change-Id: I644db7635010da8bc29d87926a64c4e6939d7c83
Reviewed-by: Qt CI Patch Build Bot <ci_patchbuild_bot@qt.io>
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

2 files changed, 36 insertions, 3 deletions

diff --git a/src/libs/utils/smallstring.h b/src/libs/utils/smallstring.h
index a91b1665392..530022f475c 100644
--- a/src/libs/utils/smallstring.h
+++ b/src/libs/utils/smallstring.h
@@ -425,13 +425,28 @@ public:
         size_type oldSize = size();
         size_type newSize = oldSize + string.size();
 
-        reserve(optimalCapacity(newSize));
+        if (fitsNotInCapacity(newSize))
+            reserve(optimalCapacity(newSize));
+
         std::char_traits<char>::copy(std::next(data(), static_cast<std::ptrdiff_t>(oldSize)),
                                      string.data(),
                                      string.size());
         setSize(newSize);
     }
 
+    void append(char character) noexcept
+    {
+        size_type oldSize = size();
+        size_type newSize = oldSize + 1;
+
+        if (fitsNotInCapacity(newSize))
+            reserve(optimalCapacity(newSize));
+
+        auto current = std::next(data(), static_cast<std::ptrdiff_t>(oldSize));
+        *current = character;
+        setSize(newSize);
+    }
+
     template<typename Type, typename = std::enable_if_t<std::is_arithmetic_v<Type>>>
     void append(Type number)
     {
@@ -498,6 +513,13 @@ public:
         return *this;
     }
 
+    BasicSmallString &operator+=(char character) noexcept
+    {
+        append(character);
+
+        return *this;
+    }
+
     BasicSmallString &operator+=(QStringView string) noexcept
     {
         append(string);
@@ -698,8 +720,10 @@ unittest_public:
 
     bool fitsNotInCapacity(size_type capacity) const noexcept
     {
-        return (isShortString() && capacity > shortStringCapacity())
-               || (!isShortString() && capacity > m_data.reference.capacity);
+        if (isShortString())
+            return capacity > shortStringCapacity();
+
+        return capacity > m_data.reference.capacity;
     }
 
     static size_type optimalHeapCapacity(const size_type size) noexcept
diff --git a/tests/unit/tests/unittests/utils/smallstring-test.cpp b/tests/unit/tests/unittests/utils/smallstring-test.cpp
index ac979ef65c3..3594c838c96 100644
--- a/tests/unit/tests/unittests/utils/smallstring-test.cpp
+++ b/tests/unit/tests/unittests/utils/smallstring-test.cpp
@@ -959,6 +959,15 @@ TEST(SmallString, append_float)
     ASSERT_THAT(text, Eq("some text123.456"));
 }
 
+TEST(SmallString, append_character)
+{
+    SmallString text("some text");
+
+    text += 'x';
+
+    ASSERT_THAT(text, Eq("some textx"));
+}
+
 TEST(SmallString, to_byte_array)
 {
     SmallString text("some text");