[cindex.py] fix infinite iteration of compilation database CompileCommands

Patch by David Röthlisberger

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159926 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/bindings/python/clang/cindex.py b/bindings/python/clang/cindex.py
index afbfe3d..0aea466 100644
--- a/bindings/python/clang/cindex.py
+++ b/bindings/python/clang/cindex.py
@@ -2162,7 +2162,7 @@
 
     def __getitem__(self, i):
         cc = CompileCommands_getCommand(self.ccmds, i)
-        if cc is None:
+        if not cc:
             raise IndexError
         return CompileCommand(cc, self)
 
diff --git a/bindings/python/tests/cindex/test_cdb.py b/bindings/python/tests/cindex/test_cdb.py
index 38de4b1..374f99b 100644
--- a/bindings/python/tests/cindex/test_cdb.py
+++ b/bindings/python/tests/cindex/test_cdb.py
@@ -61,6 +61,14 @@
         for arg, exp in zip(cmds[i].arguments, expected[i]['line']):
             assert arg.spelling == exp
 
+def test_compilecommand_iterator_stops():
+    """Check that iterator stops after the correct number of elements"""
+    cdb = CompilationDatabase.fromDirectory(kInputsDir)
+    count = 0
+    for cmd in cdb.getCompileCommands('/home/john.doe/MyProject/project2.cpp'):
+        count += 1
+        assert count <= 2
+
 def test_compilationDB_references():
     """Ensure CompilationsCommands are independent of the database"""
     cdb = CompilationDatabase.fromDirectory(kInputsDir)