From bff4e0cb8194b490ab11370e1485e61417b01210 Mon Sep 17 00:00:00 2001
From: pharshalp <pharshalp@gmail.com>
Date: Mon, 12 Nov 2018 18:20:18 -0500
Subject: [PATCH 1/2] postpone casting to float to allow hist vals to remain
 ints when the input data is ints and no weighting is used

---
 lib/matplotlib/axes/_axes.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index 9037674780e2..ae0fb86cfeab 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -6635,7 +6635,6 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
             # this will automatically overwrite bins,
             # so that each histogram uses the same bins
             m, bins = np.histogram(x[i], bins, weights=w[i], **hist_kwargs)
-            m = m.astype(float)  # causes problems later if it's an int
             if mlast is None:
                 mlast = np.zeros(len(bins)-1, m.dtype)
             if stacked:
@@ -6647,6 +6646,9 @@ def hist(self, x, bins=None, range=None, density=None, weights=None,
         # histograms together is 1
         if stacked and density:
             db = np.diff(bins)
+            # casting as float to avoid issues with division result being
+            # stored in the same numpy array (in case the dtype is int).
+            tops = [m.astype(float) for m in tops]
             for m in tops:
                 m[:] = (m / db) / tops[-1].sum()
         if cumulative:

From 6565e495913114c9d5466ef2c37ec6b3431acbd4 Mon Sep 17 00:00:00 2001
From: pharshalp <pharshalp@gmail.com>
Date: Mon, 12 Nov 2018 18:48:52 -0500
Subject: [PATCH 2/2] Added test to check if hist of ints returns ints in no
 weighting

---
 lib/matplotlib/tests/test_axes.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
index f6e3f733b95b..6851118338ba 100644
--- a/lib/matplotlib/tests/test_axes.py
+++ b/lib/matplotlib/tests/test_axes.py
@@ -1492,6 +1492,12 @@ def test_barh_tick_label():
             align='center')
 
 
+def test_int_hist():
+    fig, ax = plt.subplots()
+    n, _, _ = ax.hist(np.arange(10))
+    assert n.dtype == np.int
+
+
 @image_comparison(baseline_images=['hist_log'],
                   remove_text=True)
 def test_hist_log():