Make linewise bracketed paste match P behavior

This is experimental. Testing will reveal if this is the desired
behavior.

src/input_handler.cc

@@ -77,13 +77,17 @@ void InputMode::paste(StringView content)
     try
     {
         Buffer& buffer = context().buffer();
+        const bool linewise = not content.empty() and content.back() == '\n';
         ScopedEdition edition{context()};
         ScopedSelectionEdition selection_edition{context()};
-        context().selections().for_each([&buffer, content=std::move(content)]
+        context().selections().for_each([&buffer, content=std::move(content), linewise]
                                         (size_t index, Selection& sel) {
-            BufferRange range = buffer.insert(sel.min(), content);
-            sel.min() = range.begin;
-            sel.max() = range.end > range.begin ? buffer.char_prev(range.end) : range.begin;
+            auto& min = sel.min();
+            auto& max = sel.max();
+            BufferRange range =
+                buffer.insert(paste_pos(buffer, min, max, PasteMode::Insert, linewise), content);
+            min = range.begin;
+            max = range.end > range.begin ? buffer.char_prev(range.end) : range.begin;
         }, false);
     }
     catch (Kakoune::runtime_error& error)

src/normal.cc

@@ -657,13 +657,6 @@ void change(Context& context, NormalParams params)
     enter_insert_mode<InsertMode::Replace>(context, params);
 }
 
-enum class PasteMode
-{
-    Append,
-    Insert,
-    Replace
-};
-
 BufferCoord paste_pos(Buffer& buffer, BufferCoord min, BufferCoord max, PasteMode mode, bool linewise)
 {
     switch (mode)

src/normal.hh

@@ -10,6 +10,7 @@
 namespace Kakoune
 {
 
+class Buffer;
 class Context;
 
 struct no_selections_remaining : runtime_error
@@ -40,6 +41,15 @@ struct KeyInfo
 String build_autoinfo_for_mapping(const Context& context, KeymapMode mode,
                                   ConstArrayView<KeyInfo> built_ins);
 
+enum class PasteMode
+{
+    Append,
+    Insert,
+    Replace
+};
+
+BufferCoord paste_pos(Buffer& buffer, BufferCoord min, BufferCoord max, PasteMode mode, bool linewise);
+
 }
 
 #endif // normal_hh_INCLUDED