Mark syntax errors in Execute SQL tab

If a syntax error is reported by SQLite during execution in the Execute
SQL tab of the main window try to locate the problematic SQL statement
and highlight it using a red squiggling line.

src/MainWindow.cpp

@@ -683,17 +683,24 @@ void MainWindow::executeQuery()
     // Get SQL code to execute. This depends on the button that's been pressed
     QString query;
     bool singleStep = false;
+    int execution_start_line = 0;
+    int execution_start_index = 0;
     if(sender()->objectName() == "actionSqlExecuteLine")
     {
         int cursor_line, cursor_index;
         sqlWidget->getEditor()->getCursorPosition(&cursor_line, &cursor_index);
-        query = sqlWidget->getEditor()->text().mid(cursor_index);
+        execution_start_line = cursor_line;
+        while(cursor_line < sqlWidget->getEditor()->lines())
+            query += sqlWidget->getEditor()->text(cursor_line++);
         singleStep = true;
     } else {
         // if a part of the query is selected, we will only execute this part
         query = sqlWidget->getSelectedSql();
+        int dummy;
         if(query.isEmpty())
             query = sqlWidget->getSql();
+        else
+            sqlWidget->getEditor()->getSelection(&execution_start_line, &execution_start_index, &dummy, &dummy);
     }
     if (query.isEmpty())
         return;
@@ -715,17 +722,25 @@ void MainWindow::executeQuery()
     // gets finalized, see http://www.sqlite.org/lang_transaction.html
     db.setRestorePoint();
 
+    // Remove any error indicators
+    sqlWidget->getEditor()->clearIndicatorRange(0, 0,
+                                                sqlWidget->getEditor()->lines(), sqlWidget->getEditor()->lineLength(sqlWidget->getEditor()->lines()),
+                                                sqlWidget->getEditor()->getErrorIndicatorNumber());
+
     //Accept multi-line queries, by looping until the tail is empty
     QElapsedTimer timer;
     timer.start();
     do
     {
+        int tail_length_before = tail_length;
         const char* qbegin = tail;
-        sql3status = sqlite3_prepare_v2(db._db,tail, tail_length,
-                            &vm, &tail);
+        sql3status = sqlite3_prepare_v2(db._db,tail, tail_length, &vm, &tail);
         QString queryPart = QString::fromUtf8(qbegin, tail - qbegin);
         tail_length -= (tail - qbegin);
-        if (sql3status == SQLITE_OK){
+        int execution_end_index = execution_start_index + tail_length_before - tail_length;
+
+        if (sql3status == SQLITE_OK)
+        {
             sql3status = sqlite3_step(vm);
             sqlite3_finalize(vm);
 
@@ -778,7 +793,11 @@ void MainWindow::executeQuery()
         } else {
             statusMessage = QString::fromUtf8((const char*)sqlite3_errmsg(db._db)) +
                     ": " + queryPart;
+            sqlWidget->getEditor()->fillIndicatorRange(execution_start_line, execution_start_index, execution_start_line, execution_end_index,
+                                                       sqlWidget->getEditor()->getErrorIndicatorNumber());
         }
+
+        execution_start_index = execution_end_index;
     } while( tail && *tail != 0 && (sql3status == SQLITE_OK || sql3status == SQLITE_DONE));
     sqlWidget->finishExecution(statusMessage);
     updatePlot(sqlWidget->getModel());

src/sqltextedit.cpp

@@ -82,6 +82,10 @@ SqlTextEdit::SqlTextEdit(QWidget* parent) :
 
     // Enable folding
     setFolding(QsciScintilla::BoxedTreeFoldStyle);
+
+    // Create error indicator
+    errorIndicatorNumber = indicatorDefine(QsciScintilla::SquiggleIndicator);
+    setIndicatorForegroundColor(Qt::red, errorIndicatorNumber);
 }
 
 SqlTextEdit::~SqlTextEdit()

src/sqltextedit.h

@@ -17,6 +17,8 @@ public:
     explicit SqlTextEdit(QWidget *parent = 0);
     virtual ~SqlTextEdit();
 
+    int getErrorIndicatorNumber() const { return errorIndicatorNumber; }
+
     static SqlUiLexer* sqlLexer;
 
 public slots:
@@ -28,6 +30,8 @@ protected:
 private:
     void setupSyntaxHighlightingFormat(const QString& settings_name, int style);
 
+    int errorIndicatorNumber;
+
 private slots:
     void updateLineNumberAreaWidth();
 };