empty-qstringliteral: Improve readme

QStringLiteral().isNull() is false

1 files changed, 4 insertions, 1 deletions

diff --git a/docs/checks/README-empty-qstringliteral.md b/docs/checks/README-empty-qstringliteral.md
index 3c78ba67..fe8ba4ef 100644
--- a/docs/checks/README-empty-qstringliteral.md
+++ b/docs/checks/README-empty-qstringliteral.md
@@ -3,4 +3,7 @@
 Suggests to use an empty `QString` instead of an empty `QStringLiteral`.
 The later causes unneeded code bloat.
 
-You should use `QString()` instead of `QStringLiteral()` and use `QString("")` instead of `QStringLiteral("")`.
+You should use `QString()` instead of `QStringLiteral()` and `QStringLiteral("")`.
+
+Note: Beware that `QString().isNull()` is `true` while both `QStringLiteral().isNull()` and `QStringLiteral("").isNull()` are `false`.
+So be sure not to introduce subtle bugs when doing such replacements. In most cases it's simply a matter of using `isEmpty()` instead, which is `true` for all cases above.