From f7d7eeb24693f53bfbec7c29005f54da34bb5c2c Mon Sep 17 00:00:00 2001
From: Jose Rodriguez <boriel@gmail.com>
Date: Wed, 27 May 2020 23:59:58 +0200
Subject: [PATCH] Fix crash on unknown constant dimension

---
 symbols/bound.py                     | 7 +++++++
 tests/functional/dim_const_crash.bas | 4 ++++
 2 files changed, 11 insertions(+)
 create mode 100644 tests/functional/dim_const_crash.bas

diff --git a/symbols/bound.py b/symbols/bound.py
index 7cf55ddc3..7f6d32806 100644
--- a/symbols/bound.py
+++ b/symbols/bound.py
@@ -50,8 +50,15 @@ def make_node(lower, upper, lineno):
 
         if isinstance(lower, SymbolVAR):
             lower = lower.value
+            if lower is None:  # semantic error
+                syntax_error(lineno, "Unknown lower bound for array dimension")
+                return
+
         if isinstance(upper, SymbolVAR):
             upper = upper.value
+            if upper is None:  # semantic error
+                syntax_error(lineno, "Unknown upper bound for array dimension")
+                return
 
         lower.value = int(lower.value)
         upper.value = int(upper.value)
diff --git a/tests/functional/dim_const_crash.bas b/tests/functional/dim_const_crash.bas
new file mode 100644
index 000000000..e0f27a17d
--- /dev/null
+++ b/tests/functional/dim_const_crash.bas
@@ -0,0 +1,4 @@
+
+const MAXMOBS as ubyte = MHEIGHT
+dim mobCoords(0 to MAXMOBS, 0 to 1) as ubyte
+