3 files changed, 63 insertions, 0 deletions
diff --git a/testsuite/synth/issue662/issue.vhdl b/testsuite/synth/issue662/issue.vhdl
new file mode 100644
index 000000000..1404b9ecd
--- /dev/null
+++ b/testsuite/synth/issue662/issue.vhdl
@@ -0,0 +1,16 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+entity issue is
+  port (clk, a, b : std_logic);
+end entity issue;
+
+
+architecture psl of issue is
+begin
+  -- All is sensitive to rising edge of clk
+  default clock is rising_edge(clk);
+
+  -- This assertion should fail
+  stable_1 : assert always (a -> prev(b) = b);
+end architecture psl;
diff --git a/testsuite/synth/issue662/tb_issue.vhdl b/testsuite/synth/issue662/tb_issue.vhdl
new file mode 100644
index 000000000..c679b059f
--- /dev/null
+++ b/testsuite/synth/issue662/tb_issue.vhdl
@@ -0,0 +1,34 @@
+library ieee;
+  use ieee.std_logic_1164.all;
+
+entity tb_issue is
+end entity tb_issue;
+
+
+architecture psl of tb_issue is
+  procedure seq (s : string; signal clk : std_logic; signal o : out std_logic)
+  is
+  begin
+    for i in s'range loop
+      wait until rising_edge(clk);
+      case s(i) is
+        when '0' | '_' => o <= '0';
+        when '1' | '-' => o <= '1';
+        when others    => o <= 'X';
+      end case;
+    end loop;
+    wait;
+  end seq;
+
+  signal a, b : std_logic := '0';
+  signal clk   : std_logic := '1';
+
+begin
+  dut: entity work.issue port map (clk, a, b);
+
+  clk <= not clk after 500 ps;
+
+  --            0123456789012345
+  SEQ_A : seq ("__-__-____-__-__", clk, a);
+  SEQ_B : seq ("____--_______-__", clk, b);
+end architecture psl;
diff --git a/testsuite/synth/issue662/testsuite.sh b/testsuite/synth/issue662/testsuite.sh
new file mode 100755
index 000000000..9f266b29d
--- /dev/null
+++ b/testsuite/synth/issue662/testsuite.sh
@@ -0,0 +1,13 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+GHDL_STD_FLAGS=--std=08
+synth_analyze issue
+analyze tb_issue.vhdl
+elab_simulate_failure tb_issue --stop-time=20ns --asserts=disable-at-0 --assert-level=error
+elab_simulate tb_issue --stop-time=10ns --asserts=disable-at-0 --assert-level=error
+
+clean
+
+echo "Test successful"