From 958b1c366e985971ce274b4c2d38cb909435ba9c Mon Sep 17 00:00:00 2001
From: Jerry Vinokurov <grapesmoker@gmail.com>
Date: Fri, 17 Jan 2025 12:29:03 -0500
Subject: [PATCH] fix: support the case of multiple line segments each with one
 vdim (#6492)

---
 holoviews/plotting/bokeh/path.py              | 13 ++++++++++--
 .../tests/plotting/bokeh/test_pathplot.py     | 21 +++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/holoviews/plotting/bokeh/path.py b/holoviews/plotting/bokeh/path.py
index 883d900d31..cebdace513 100644
--- a/holoviews/plotting/bokeh/path.py
+++ b/holoviews/plotting/bokeh/path.py
@@ -52,8 +52,17 @@ def _element_transform(self, transform, element, ranges):
                 else:
                     new_data.append(d)
             return np.array(new_data)
-        return np.concatenate([transform.apply(el, ranges=ranges, flat=True)
-                               for el in element.split()])
+
+        transformed = []
+        for el in element.split():
+            new_el = transform.apply(el, ranges=ranges, flat=True)
+            if len(new_el) == 1:
+                kdim_length = len(el[el.kdims[0]])
+                transformed.append(np.tile(new_el, kdim_length - 1))
+            else:
+                transformed.append(new_el)
+
+        return np.concatenate(transformed)
 
     def _hover_opts(self, element):
         cdim = element.get_dimension(self.color_index)
diff --git a/holoviews/tests/plotting/bokeh/test_pathplot.py b/holoviews/tests/plotting/bokeh/test_pathplot.py
index 8185cdcee0..a743887485 100644
--- a/holoviews/tests/plotting/bokeh/test_pathplot.py
+++ b/holoviews/tests/plotting/bokeh/test_pathplot.py
@@ -193,6 +193,27 @@ def test_path_continuously_varying_color_legend_with_labels(self):
         self.assertEqual(property_to_dict(item.label), legend)
         self.assertEqual(item.renderers, [plot.handles['glyph_renderer']])
 
+    def test_path_multiple_segments_with_single_vdim(self):
+
+        # two segments, each with its own color
+        data = [{
+            'x': [0, 1, 1],
+            'y': [0, 0, 1],
+            'color': '#FF0000',
+        }, {
+            'x': [0, 0, 1],
+            'y': [0, 1, 1],
+            'color': '#0000FF',
+        }]
+
+        path = Path(data, vdims='color').opts(line_color='color')
+        plot = bokeh_renderer.get_plot(path)
+        cds = plot.handles['cds']
+        source = plot.handles['source']
+        np.testing.assert_equal(source.data['xs'], [np.array([0, 1]), np.array([1, 1]), np.array([0, 0]), np.array([0, 1])])
+        np.testing.assert_equal(source.data['ys'], [np.array([0, 0]), np.array([0, 1]), np.array([0, 1]), np.array([1, 1])])
+        assert list(cds.data['line_color']) == ['#FF0000', '#FF0000', '#0000FF', '#0000FF']
+
 
 class TestPolygonPlot(TestBokehPlot):