fixes critical 'do' parsing bug

1 files changed, 79 insertions, 0 deletions

diff --git a/tests/parser/tdo.nim b/tests/parser/tdo.nim
new file mode 100644
index 000000000..7bd1f7411
--- /dev/null
+++ b/tests/parser/tdo.nim
@@ -0,0 +1,79 @@
+discard """
+  output: '''true
+true
+true
+true inner B'''
+"""
+
+template withValue(a, b, c, d, e: untyped) =
+  if c:
+    d
+  else:
+    e
+
+template withValue(a, b, c, d: untyped) =
+  if c:
+    d
+
+const
+  EVENT_READ = 1
+  EVENT_WRITE = 2
+  FLAG_HANDLE = 3
+  EVENT_MASK = 3
+
+var s: string
+
+proc main =
+  var value = false
+  var fd = 8888
+  var event = 0
+  s.withValue(fd, value) do:
+    if value:
+      var oe = (EVENT_MASK)
+      if (oe xor event) != 0:
+        if (oe and EVENT_READ) != 0 and (event and EVENT_READ) == 0:
+          discard
+        if (oe and EVENT_WRITE) != 0 and (event and EVENT_WRITE) == 0:
+          discard
+        if (oe and EVENT_READ) == 0 and (event and EVENT_READ) != 0:
+          discard
+        if (oe and EVENT_WRITE) == 0 and (event and EVENT_WRITE) != 0:
+          discard
+    else:
+      raise newException(ValueError, "error")
+  do:
+    raise newException(ValueError, "Descriptor is not registered in queue")
+
+proc main2 =
+  var unused = 8
+  # test 'then' branch:
+  s.withValue(unused, true) do:
+    echo "true"
+  do:
+    echo "false"
+
+  # test overloading:
+  s.withValue(unused, false) do:
+    echo "cannot come here"
+
+  # test 'else' branch:
+  s.withValue(unused, false) do:
+    echo "false"
+  do:
+    echo "true"
+
+  # test proper nesting:
+  s.withValue(unused, false) do:
+    echo "false"
+    s.withValue(unused, false) do:
+      echo "false inner A"
+    do:
+      echo "true inner A"
+  do:
+    echo "true"
+    s.withValue(unused, false) do:
+      echo "false inner B"
+    do:
+      echo "true inner B"
+
+main2()