Detect Thai writing system support from the font's Code Page Bitfields

https://msdn.microsoft.com/en-us/library/windows/desktop/dd317754(v=vs.85).aspx

Change-Id: I893746210dc71b9de6f6c064fd9fcaf6340e3c71
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@theqtcompany.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gui/text/qplatformfontdatabase.cpp b/src/gui/text/qplatformfontdatabase.cpp
index 3c3000da4d..eec9dd905e 100644
--- a/src/gui/text/qplatformfontdatabase.cpp
+++ b/src/gui/text/qplatformfontdatabase.cpp
@@ -522,6 +522,7 @@ enum {
     VietnameseCsbBit = 8,
     SimplifiedChineseCsbBit = 18,
     TraditionalChineseCsbBit = 20,
+    ThaiCsbBit = 16,
     JapaneseCsbBit = 17,
     KoreanCsbBit = 19,
     KoreanJohabCsbBit = 21
@@ -579,6 +580,11 @@ QSupportedWritingSystems QPlatformFontDatabase::writingSystemsFromTrueTypeBits(q
         hasScript = true;
         //qDebug("font %s supports Arabic", familyName.latin1());
     }
+    if (codePageRange[0] & (1 << ThaiCsbBit)) {
+        writingSystems.setSupported(QFontDatabase::Thai);
+        hasScript = true;
+        //qDebug("font %s supports Thai", familyName.latin1());
+    }
     if (codePageRange[0] & (1 << VietnameseCsbBit)) {
         writingSystems.setSupported(QFontDatabase::Vietnamese);
         hasScript = true;