QgsCodeEditorSQL: make autocompletion case insensitive when APIs are …

…set on the lexer

src/gui/qgscodeeditorsql.cpp

@@ -39,11 +39,27 @@ QgsCodeEditorSQL::~QgsCodeEditorSQL()
 {
 }
 
+/** Internal use.
+
+   setAutoCompletionCaseSensitivity( false ) is not sufficient when installing
+   a lexer, since its caseSensitive() method is actually used, and defaults
+   to true.
+   @note not available in Python bindings
+*/
+class QgsCaseInsensitiveLexerSQL: public QsciLexerSQL
+{
+  public:
+    //! constructor
+    QgsCaseInsensitiveLexerSQL( QObject *parent = 0 ) : QsciLexerSQL( parent ) {}
+
+    bool caseSensitive() const override { return false; }
+};
+
 void QgsCodeEditorSQL::setSciLexerSQL()
 {
   QFont font = getMonospaceFont();
 
-  QsciLexerSQL* sqlLexer = new QsciLexerSQL( this );
+  QsciLexerSQL* sqlLexer = new QgsCaseInsensitiveLexerSQL( this );
   sqlLexer->setDefaultFont( font );
   sqlLexer->setFont( font, -1 );
   font.setBold( true );