diff --git a/tests/decode/check.sh b/tests/decode/check.sh
index 79a06c37cd..95445a0115 100755
--- a/tests/decode/check.sh
+++ b/tests/decode/check.sh
@@ -15,4 +15,10 @@ for i in err_*.decode; do
     fi
 done
 
+for i in succ_*.decode; do
+    if ! $PYTHON $DECODETREE $i > /dev/null 2> /dev/null; then
+        echo FAIL:$i 1>&2
+    fi
+done
+
 exit $E
diff --git a/tests/decode/err_pattern_group_empty.decode b/tests/decode/err_pattern_group_empty.decode
new file mode 100644
index 0000000000..abbff6b528
--- /dev/null
+++ b/tests/decode/err_pattern_group_empty.decode
@@ -0,0 +1,6 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# empty groups are not allowed
+{
+}
diff --git a/tests/decode/err_pattern_group_ident1.decode b/tests/decode/err_pattern_group_ident1.decode
new file mode 100644
index 0000000000..3e65fab2f9
--- /dev/null
+++ b/tests/decode/err_pattern_group_ident1.decode
@@ -0,0 +1,10 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+%sub1 0:8
+
+# Make sure that indentation is enforced
+{
+    top      00000000 00000000 00000000 00000000
+    sub1     00000000 00000000 00000000 ........ %sub1
+}
diff --git a/tests/decode/err_pattern_group_ident2.decode b/tests/decode/err_pattern_group_ident2.decode
new file mode 100644
index 0000000000..bc859233b1
--- /dev/null
+++ b/tests/decode/err_pattern_group_ident2.decode
@@ -0,0 +1,11 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+%sub1 0:8
+
+# Make sure that indentation is enforced
+{
+  top      00000000 00000000 00000000 00000000
+  sub1     00000000 00000000 00000000 ........ %sub1
+# comments are suposed to be indented
+}
diff --git a/tests/decode/err_pattern_group_nest1.decode b/tests/decode/err_pattern_group_nest1.decode
new file mode 100644
index 0000000000..92e971c3c5
--- /dev/null
+++ b/tests/decode/err_pattern_group_nest1.decode
@@ -0,0 +1,13 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+%sub1 0:8
+%sub2 8:8
+%sub3 16:8
+%sub4 24:8
+
+# Groups with no overlap are supposed to fail
+{
+  top  00000000 00000000 00000000 00000000
+  sub4 ........ ........ ........ ........ %sub1 %sub2 %sub3 %sub4
+}
diff --git a/tests/decode/succ_pattern_group_nest1.decode b/tests/decode/succ_pattern_group_nest1.decode
new file mode 100644
index 0000000000..77b0f48b49
--- /dev/null
+++ b/tests/decode/succ_pattern_group_nest1.decode
@@ -0,0 +1,22 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+%sub1 0:8
+%sub2 8:8
+%sub3 16:8
+%sub4 24:7
+
+# Make sure deep netsting works, as few targets will actually exercise it
+{
+  top        00000000 00000000 00000000 00000000
+  {
+    sub1     00000000 00000000 00000000 ........ %sub1
+    {
+      sub2   00000000 00000000 ........ ........ %sub1 %sub2
+      {
+        sub3 00000000 ........ ........ ........ %sub1 %sub2 %sub3
+        sub4 0....... ........ ........ ........ %sub1 %sub2 %sub3 %sub4
+      }
+    }
+  }
+}