diff --git a/src/render/katerenderer.cpp b/src/render/katerenderer.cpp
--- a/src/render/katerenderer.cpp
+++ b/src/render/katerenderer.cpp
@@ -589,18 +589,51 @@
 
         QVector<QTextLayout::FormatRange> additionalFormats;
         if (range->length() > 0) {
+            if (drawSelection) {
+                additionalFormats = decorationsForLine(range->textLine(), range->line(), true);
+            }
+
+            // Check if there's any format need to be fill into the gap.
+            auto formats = range->layout()->formats();
+            if (!formats.isEmpty() || !additionalFormats.isEmpty()) {
+                QVector<QTextLayout::FormatRange> additionalFormatsCopy = formats;
+                additionalFormatsCopy += additionalFormats;
+                additionalFormatsCopy.append(QTextLayout::FormatRange());
+                // Add this dummy selection to further drawing.
+                additionalFormatsCopy.back().start = 0;
+                additionalFormatsCopy.back().length = INT_MAX;
+                additionalFormatsCopy.back().format.setForeground(Qt::transparent);
+                additionalFormatsCopy.back().format.setBackground(Qt::transparent);
+                for (int i = 0 ; i < formats.size() + additionalFormats.size(); i++) {
+                    additionalFormatsCopy[i].format.clearForeground();
+                }
+                for (int i = 0; i < range->layout()->lineCount(); i++) {
+                    auto line = range->layout()->lineAt(i);
+                    int y = qRound(range->layout()->lineAt(i).y());
+                    // Right now, y should always be multiply of lineHeight.
+                    if (auto yOffset = y % lineHeight()) {
+                        auto rect = line.rect();
+                        if (rect.height() > 0) {
+                            rect.moveTop(line.y() - yOffset);
+                            rect.setHeight(yOffset);
+                            auto diffHeight = yOffset;
+                            auto yStart = -yOffset;
+                            // We use a loop here just in case yOffset is very large, which should be rare.
+                            while (diffHeight > 0) {
+                                range->layout()->draw(&paint, QPoint(-xStart, yStart), additionalFormatsCopy, rect);
+                                yStart += rect.height();
+                                diffHeight -= rect.height();
+                            }
+                        }
+                    }
+                }
+            }
             // We may have changed the pen, be absolutely sure it gets set back to
             // normal foreground color before drawing text for text that does not
             // set the pen color
             paint.setPen(attribute(KTextEditor::dsNormal)->foreground().color());
             // Draw the text :)
-            if (drawSelection) {
-                additionalFormats = decorationsForLine(range->textLine(), range->line(), true);
-                range->layout()->draw(&paint, QPoint(-xStart, 0), additionalFormats);
-
-            } else {
-                range->layout()->draw(&paint, QPoint(-xStart, 0));
-            }
+            range->layout()->draw(&paint, QPoint(-xStart, 0), additionalFormats);
         }
 
         QBrush backgroundBrush;
@@ -980,6 +1013,10 @@
      * qreal fontHeight = font.ascent() + font.descent();
      */
     m_fontHeight = qMax(1, qCeil(m_fontMetrics.ascent() + m_fontMetrics.descent()));
+    // Try to use representitve character from English, Chinese, Japanese
+    // and Korean to calculate the line height.
+    // The characters being tested are "AHIygあ你말".
+    m_fontHeight = qMax(m_fontHeight, qCeil(m_fontMetrics.boundingRect(QString::fromUtf8("AHIyg\xe3\x81\x82\xe4\xbd\xa0\xeb\xa7\x90")).height()));
 }
 
 void KateRenderer::updateMarkerSize()
@@ -1088,8 +1125,11 @@
 
         // we include the leading, this must match the ::updateFontHeight code!
         line.setLeadingIncluded(true);
-
-        line.setPosition(QPoint(line.lineNumber() ? shiftX : firstLineOffset, height));
+        qreal lineOffset = 0;
+        if (line.height() < lineHeight()) {
+            lineOffset = lineHeight() - line.height();
+        }
+        line.setPosition(QPoint(line.lineNumber() ? shiftX : firstLineOffset, height + lineOffset));
 
         if (needShiftX && line.width() > 0) {
             needShiftX = false;