Merge pull request #153 from navytux/y/fs-ro

FileStorage: Report problem on read-only open of non-existent file

src/ZODB/FileStorage/FileStorage.py

@@ -267,6 +267,10 @@ class FileStorage(
                 if exc.errno == errno.EFBIG:
                     # The file is too big to open.  Fail visibly.
                     raise
+                if read_only:
+                    # When open request is read-only we do not want to create
+                    # the file
+                    raise
                 if exc.errno == errno.ENOENT:
                     # The file doesn't exist.  Create it.
                     create = 1

src/ZODB/tests/testConfig.py

@@ -73,6 +73,16 @@ class ZODBConfigTest(ConfigTestBase):
 
     def test_file_config2(self):
         path = tempfile.mktemp()
+        # first pass to actually create database file
+        self._test(
+            """
+            <zodb>
+              <filestorage>
+                path %s
+              </filestorage>
+            </zodb>
+            """ % path)
+        # write operations must be disallowed on read-only access
         cfg = """
         <zodb>
           <filestorage>

src/ZODB/tests/testFileStorage.py

@@ -689,6 +689,19 @@ def pack_with_open_blob_files():
     >>> db.close()
     """
 
+def readonly_open_nonexistent_file():
+    """
+    Make sure error is reported when non-existent file is tried to be opened
+    read-only.
+
+    >>> try:
+    ...     fs = ZODB.FileStorage.FileStorage('nonexistent.fs', read_only=True)
+    ... except Exception as e:
+    ...     # Python2 raises IOError; Python3 - FileNotFoundError
+    ...     print("error: %s" % str(e)) # doctest: +ELLIPSIS
+    error: ... No such file or directory: 'nonexistent.fs'
+    """
+
 def test_suite():
     suite = unittest.TestSuite()
     for klass in [