From 1052ba3732a40c731c4fe0fc3caae12f4af75535 Mon Sep 17 00:00:00 2001
From: John Darrington <john@darrington.wattle.id.au>
Date: Thu, 31 Mar 2016 21:51:25 +0200
Subject: [PATCH] Fixed a bug where frequencies/histogram would crash when all
 data had missing wieghts.

Found by zzuf.
---
 src/language/stats/frequencies.c    |  2 ++
 tests/language/stats/frequencies.at | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/language/stats/frequencies.c b/src/language/stats/frequencies.c
index dc18ed83c7..cb96389778 100644
--- a/src/language/stats/frequencies.c
+++ b/src/language/stats/frequencies.c
@@ -1324,6 +1324,8 @@ freq_tab_to_hist (const struct frq_proc *frq, const struct freq_tab *ft,
         }
     }
 
+  if (valid_freq <= 0)
+    return NULL;
 
   iqr = calculate_iqr (frq);
 
diff --git a/tests/language/stats/frequencies.at b/tests/language/stats/frequencies.at
index 0d6433c5b9..f0d81c3210 100644
--- a/tests/language/stats/frequencies.at
+++ b/tests/language/stats/frequencies.at
@@ -739,3 +739,25 @@ Percentiles,,.
 ])
 
 AT_CLEANUP
+
+
+AT_SETUP([FREQUENCIES histogram no valid cases])
+AT_DATA([empty.sps], [dnl
+data list notable list /x w *.
+begin data.
+1 .
+2 .
+3 .
+end data.
+
+weight by w.
+
+FREQUENCIES
+	/VARIABLES = x
+	/histogram
+	.
+])
+
+AT_CHECK([pspp empty.sps -O format=csv], [0],  [ignore])
+
+AT_CLEANUP
-- 
2.30.2