Add fallback indenter for onTypeFormatting on IndentOnly is False

In this case, the previous line should be formatted so indent it.

Fix missing current line of the buffer for rangeFormatting allowing
to reindent the current line with the fallback indenter.

For eng/ide/ada_language_server#1729

Author: Boulanger

source/ada/lsp-ada_formatter.adb

@@ -226,7 +226,7 @@ package body LSP.Ada_Formatter is
              Buffer   =>
                Document.Get_Text ((0, 0), (Value.position.line + 1, 0)),
              Span     =>
-               ((Value.position.line, 0), (Value.position.line + 1, 0)),
+               ((0, 0), (Value.position.line + 1, 0)),
              Options  => Full_Options);
       Indentation  : constant VSS.Strings.Character_Count :=
         (declare
@@ -308,6 +308,26 @@ package body LSP.Ada_Formatter is
                    (Filename => Context.URI_To_File (Document.URI),
                     Options  => Full_Options,
                     S        => Indentation * ' ')));
+
+         --  If not in indent-only mode, re-indent the previous line too
+         if not Self.Parent.Context.Get_Configuration.Indent_Only then
+            declare
+               Prev_Line   : constant Natural :=
+                 Natural'Max (Value.position.line - 1, 0);
+               Indentation : constant Natural :=
+                 (if Indent_Array (Value.position.line) = -1
+                  then 0
+                  else Indent_Array (Value.position.line));
+            begin
+               Response.Append
+                 (LSP.Ada_Handlers.Formatting.Reindent_Line
+                    (Filename   => Context.URI_To_File (Document.URI),
+                     Line       => Document.Get_Line (Prev_Line),
+                     Pos        => (Prev_Line, 0),
+                     Options    => Full_Options,
+                     New_Indent => Indentation));
+            end;
+         end if;
       end Handle_Document_With_Diagnostics;
 
       -----------------------------------------

source/ada/lsp-ada_handlers-formatting.adb

@@ -215,7 +215,7 @@ package body LSP.Ada_Handlers.Formatting is
       Buffer : constant VSS.Strings.Virtual_String :=
         (if Span = Empty_Range
          then Document.Text
-         else Document.Slice (((0, 0), Actual_Span.an_end)));
+         else Document.Slice (((0, 0), (Actual_Span.an_end.line + 1, 0))));
       --  Get the relevant buffer to indent.
       --  If no span is provided, get the whole document buffer.
       --  Otherwise get the buffer from the start of the document