From ce8b2f6a9d0f28eda93e5ad3244f70f8cd62beb5 Mon Sep 17 00:00:00 2001
From: Marc Wouts <marc.wouts@gmail.com>
Date: Sun, 14 Oct 2018 23:10:53 +0200
Subject: [PATCH] Cell metadata from ipynb on markdown cells as well #99

Compare cell content up to blank lines, and restore markdown cell metadata from ipynb
---
 jupytext/combine.py | 60 ++++++++++++++++++++++++++++-----------------
 1 file changed, 38 insertions(+), 22 deletions(-)

diff --git a/jupytext/combine.py b/jupytext/combine.py
index 6c65db4f5..f34669537 100644
--- a/jupytext/combine.py
+++ b/jupytext/combine.py
@@ -1,30 +1,46 @@
 """Combine source and outputs from two notebooks
 """
+import re
 from .cell_metadata import _IGNORE_METADATA
 
+_BLANK_LINE = re.compile(r'^\s*$')
+
+
+def same_content(ref, test):
+    """Is the content of two cells the same, except for blank lines?"""
+    ref = [line for line in ref.splitlines() if not _BLANK_LINE.match(line)]
+    test = [line for line in test.splitlines() if not _BLANK_LINE.match(line)]
+    return ref == test
+
 
 def combine_inputs_with_outputs(nb_source, nb_outputs):
-    '''Copy outputs of the second notebook into
-    the first one, for cells that have matching inputs'''
+    """Copy outputs of the second notebook into
+    the first one, for cells that have matching inputs"""
+
+    output_code_cells = [cell for cell in nb_outputs.cells if cell.cell_type == 'code']
+    output_other_cells = [cell for cell in nb_outputs.cells if cell.cell_type != 'code']
 
-    remaining_output_cells = nb_outputs.cells
     for cell in nb_source.cells:
-        if cell.cell_type != 'code':
-            continue
-
-        # Remove outputs to warranty that trust of returned
-        # notebook is that of second notebook
-        cell.execution_count = None
-        cell.outputs = []
-
-        # Fill outputs with that of second notebook
-        for i, ocell in enumerate(remaining_output_cells):
-            if ocell.cell_type == 'code' and cell.source == ocell.source:
-                cell.execution_count = ocell.execution_count
-                cell.outputs = ocell.outputs
-
-                ometadata = ocell.metadata
-                cell.metadata.update({k: ometadata[k] for k in ometadata
-                                      if k in _IGNORE_METADATA})
-                remaining_output_cells = remaining_output_cells[(i + 1):]
-                break
+        # Remove outputs to warranty that trust of returned notebook is that of second notebook
+        if cell.cell_type == 'code':
+            cell.execution_count = None
+            cell.outputs = []
+
+            for i, ocell in enumerate(output_code_cells):
+                if same_content(cell.source, ocell.source):
+                    cell.execution_count = ocell.execution_count
+                    cell.outputs = ocell.outputs
+
+                    ometadata = ocell.metadata
+                    cell.metadata.update({k: ometadata[k] for k in ometadata if k in _IGNORE_METADATA})
+                    output_code_cells = output_code_cells[(i + 1):]
+                    break
+        else:
+            # Fill outputs with that of second notebook
+            for i, ocell in enumerate(output_other_cells):
+                if cell.cell_type == ocell.cell_type and same_content(cell.source, ocell.source):
+                    ometadata = ocell.metadata
+                    cell.metadata.update({k: ometadata[k] for k in ometadata if k in _IGNORE_METADATA})
+
+                    output_other_cells = output_other_cells[(i + 1):]
+                    break