made scgi.forkpool wsgi compliant in handling exc_info

1 files changed, 34 insertions, 3 deletions

diff --git a/wsgitools/scgi/forkpool.py b/wsgitools/scgi/forkpool.py
index 90c836a..26de9ef 100644
--- a/wsgitools/scgi/forkpool.py
+++ b/wsgitools/scgi/forkpool.py
@@ -326,15 +326,42 @@ class SCGIServer:
             value = data.pop(0)
             environ[key] = value
 
+        # elements:
+        # 0 -> None: no headers set
+        # 0 -> False: set but unsent
+        # 0 -> True: sent
+        # 1 -> status string
+        # 2 -> header list
+        response_head = [None, None, None]
+
+        def sendheaders():
+            assert response_head[0] is not None # headers set
+            if response_head[0] != True:
+                response_head[0] = True
+                try:
+                    con.sendall('Status: %s\r\n%s\r\n\r\n' % (response_head[1],
+                                    '\r\n'.join(map("%s: %s".__mod__,
+                                                    response_head[2]))))
+                except socket.error:
+                    pass
+
         def dumbsend(data):
+            sendheaders()
             try:
                 con.sendall(data)
             except socket.error:
                 pass
 
         def start_response(status, headers, exc_info=None):
-            dumbsend('Status: %s\r\n%s\r\n\r\n' % (status,
-                      '\r\n'.join(map("%s: %s".__mod__, headers))))
+            if exc_info and response_head[0]:
+                try:
+                    raise exc_info[0], exc_info[1], exc_info[2]
+                finally:
+                    exc_info = None
+            assert not response_head[0] # unset or not sent
+            response_head[0] = False # set but nothing sent
+            response_head[1] = status
+            response_head[2] = headers
             return dumbsend
 
         if not environ.get("CONTENT_LENGTH", "bad").isdigit():
@@ -360,9 +387,13 @@ class SCGIServer:
         result = self.wsgiapp(environ, start_response)
         assert hasattr(result, "__iter__")
 
-        for data in result:
+        assert response_head[0] is not None
+        result_iter = iter(result)
+        for data in result_iter:
             assert isinstance(data, str)
             dumbsend(data)
+        if response_head[0] != True:
+            sendheaders()
         if hasattr(result, "close"):
             result.close()
         sfw.close()