Add test case for the bugfix

Author: ollynowell

tests/data.py

@@ -2845,6 +2845,49 @@
     ["", "", "", "", "", "LSD (0.10)  =", "5.7", "0.3", "ns", "37.8", "566.4"],
 ]
 
+data_stream_inner_outer_columns = [
+    [
+        "Outer 1",
+        "Outer 2",
+        "Long 1",
+        "Long 2",
+        "Inner",
+        "Long 3",
+    ],
+    [
+        "A1",
+        "B1",
+        "C1",
+        "D1",
+        "E1",
+        "F1",
+    ],
+    [
+        "",
+        "",
+        "C2",
+        "D2",
+        "",
+        "F2",
+    ],
+    [
+        "",
+        "",
+        "C3",
+        "D3",
+        "",
+        "F3",
+    ],
+    [
+        "",
+        "",
+        "C4",
+        "D4",
+        "",
+        "F4",
+    ],
+]
+
 data_lattice = [
     [
         "Cycle \nName",

tests/files/stream_inner_outer_columns.pdf

@@ -123,3 +123,14 @@ def test_stream_duplicated_text(testdir):
     filename = os.path.join(testdir, "birdisland.pdf")
     tables = camelot.read_pdf(filename, flavor="stream")
     assert_frame_equal(df, tables[0].df)
+
+
+def test_stream_inner_outer_columns(testdir):
+    df = pd.DataFrame(data_stream_inner_outer_columns)
+
+    filename = os.path.join(testdir, "stream_inner_outer_columns.pdf")
+    tables = camelot.read_pdf(
+        filename,
+        flavor="stream",
+    )
+    assert_frame_equal(df, tables[0].df)