4 files changed, 46 insertions, 0 deletions
diff --git a/testsuite/synth/issue1596/ent.vhdl b/testsuite/synth/issue1596/ent.vhdl
new file mode 100644
index 000000000..ff86d620b
--- /dev/null
+++ b/testsuite/synth/issue1596/ent.vhdl
@@ -0,0 +1,15 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+-- Instatiated component ---
+entity v is
+	-- input is unconstrained
+	port (input : in std_logic_vector);
+end;
+
+architecture RTL of v is
+	constant bits : positive := 4;
+	signal i : std_logic_vector(bits - 1 downto 0);
+begin
+	i <= input;
+end;
diff --git a/testsuite/synth/issue1596/ent_bug.vhdl b/testsuite/synth/issue1596/ent_bug.vhdl
new file mode 100644
index 000000000..3002995cf
--- /dev/null
+++ b/testsuite/synth/issue1596/ent_bug.vhdl
@@ -0,0 +1,11 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use work.v;
+
+-- TOP BUG ---
+entity ent_bug is end;
+architecture RTL of ent_bug is
+begin
+	inst_v : entity v
+	port map (input => "0000");
+end;
diff --git a/testsuite/synth/issue1596/ent_working.vhdl b/testsuite/synth/issue1596/ent_working.vhdl
new file mode 100644
index 000000000..d311b7d76
--- /dev/null
+++ b/testsuite/synth/issue1596/ent_working.vhdl
@@ -0,0 +1,12 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use work.v;
+
+-- TOP WORKING ---
+entity ent_working is end;
+architecture RTL of ent_working is
+	signal a : std_logic_vector(3 downto 0) := "0101";
+begin
+	inst_v : entity v
+	port map (input => a);
+end;
diff --git a/testsuite/synth/issue1596/testsuite.sh b/testsuite/synth/issue1596/testsuite.sh
new file mode 100755
index 000000000..f9c9fdd54
--- /dev/null
+++ b/testsuite/synth/issue1596/testsuite.sh
@@ -0,0 +1,8 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+synth ent.vhdl ent_working.vhdl -e > syn_working.vhdl
+synth ent.vhdl ent_bug.vhdl -e > syn_bug.vhdl
+
+echo "Test successful"