1 files changed, 18 insertions, 0 deletions
diff --git a/tests/zlib.test b/tests/zlib.test
index 7a486ba..93c00f1 100644
--- a/tests/zlib.test
+++ b/tests/zlib.test
@@ -875,6 +875,24 @@ test zlib-11.3 {Bug 3595576 variant} -setup {
 } -cleanup {
     removeFile $file
 } -returnCodes error -result {can't set "noSuchNs::foo": parent namespace doesn't exist}
+
+test zlib-12.1 {Tk Bug 9eb55debc5} -constraints zlib -setup {
+    set stream [zlib stream compress]
+} -body {
+    set opts {}
+    for {set y 0} {$y < 60} {incr y} {
+	for {set line {};set x 0} {$x < 100} {incr x} {
+	    append line [binary format ccc $x $y 128]
+	}
+	if {$y == 59} {
+	    set opts -finalize
+	}
+	$stream put {*}$opts $line
+    }
+    string length [$stream get]
+} -cleanup {
+    $stream close
+} -result 12026
 
 ::tcltest::cleanupTests
 return