1 files changed, 3 insertions, 0 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c
index 58c7b3c..6bf28a1 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -2311,6 +2311,9 @@ static void
 PreserveChannelBuffer(
     ChannelBuffer *bufPtr)
 {
+    if (bufPtr->refCount == 0) {
+	Tcl_Panic("Reuse of ChannelBuffer!");
+    }
     bufPtr->refCount++;
 }