diff --git a/mozilla/layout/generic/crashtests/404140-1.html b/mozilla/layout/generic/crashtests/404140-1.html
new file mode 100644
index 00000000000..fa495caea2b
--- /dev/null
+++ b/mozilla/layout/generic/crashtests/404140-1.html
@@ -0,0 +1,7 @@
+
+
+
+
+
+a b
+
\ No newline at end of file
diff --git a/mozilla/layout/generic/crashtests/crashtests.list b/mozilla/layout/generic/crashtests/crashtests.list
index 86bfcca0c19..f90aeb54afe 100644
--- a/mozilla/layout/generic/crashtests/crashtests.list
+++ b/mozilla/layout/generic/crashtests/crashtests.list
@@ -85,6 +85,7 @@ load 398181-1.html
load 398181-2.html
load 400232-1.html
load 403576-1.html
+load 404140-1.html
load 404146-1.html
load 404204-1.html
load 406380.html
diff --git a/mozilla/layout/generic/nsTextFrameThebes.cpp b/mozilla/layout/generic/nsTextFrameThebes.cpp
index ba22627bccc..a12f798c7fd 100644
--- a/mozilla/layout/generic/nsTextFrameThebes.cpp
+++ b/mozilla/layout/generic/nsTextFrameThebes.cpp
@@ -964,7 +964,7 @@ BuildTextRuns(gfxContext* aContext, nsTextFrame* aForFrame,
scanner.ScanFrame(child);
child = child->GetNextSibling();
}
- if (forwardIterator.GetContainer() == aLineContainer && line == startLine) {
+ if (line.get() == startLine.get()) {
seenStartLine = PR_TRUE;
}
if (seenStartLine) {