From e229a33394ba9708dd895760eabc47e9dc659c92 Mon Sep 17 00:00:00 2001
From: John Darrington <john@darrington.wattle.id.au>
Date: Wed, 13 Jan 2016 09:31:42 +0100
Subject: [PATCH] EXAMINE: Extend test for empty dataset and fix bug.

Closes bug #46866
---
 src/language/stats/examine.c    | 36 +++++++++++++++++++++++----------
 tests/language/stats/examine.at |  7 ++++++-
 2 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/src/language/stats/examine.c b/src/language/stats/examine.c
index 46863cad97..295fca1a4a 100644
--- a/src/language/stats/examine.c
+++ b/src/language/stats/examine.c
@@ -1532,6 +1532,25 @@ update_n (const void *aux1, void *aux2 UNUSED, void *user_data,
   const struct examine *examine = aux1;
   struct exploratory_stats *es = user_data;
   
+  bool this_case_is_missing = false;
+  /* LISTWISE missing must be dealt with here */
+  if (!examine->missing_pw)
+    {
+      for (v = 0; v < examine->n_dep_vars; v++)
+	{
+	  const struct variable *var = examine->dep_vars[v];
+
+	  if (var_is_value_missing (var, case_data (c, var), examine->dep_excl))
+	    {
+	      es[v].missing += weight;
+	      this_case_is_missing = true;
+	    }
+	}
+    }
+
+  if (this_case_is_missing)
+    return;
+
   for (v = 0; v < examine->n_dep_vars; v++)
     {
       struct ccase *outcase ;
@@ -1588,7 +1607,7 @@ calculate_n (const void *aux1, void *aux2 UNUSED, void *user_data)
       struct casereader *reader;
       struct ccase *c;
 
-      if (examine->histogramplot)
+      if (examine->histogramplot && es[v].non_missing > 0)
         {
           /* Sturges Rule */
           double bin_width = fabs (es[v].minimum - es[v].maximum)
@@ -1655,7 +1674,7 @@ calculate_n (const void *aux1, void *aux2 UNUSED, void *user_data)
         }
       casereader_destroy (reader);
 
-      if (examine->calc_extremes > 0)
+      if (examine->calc_extremes > 0 && es[v].non_missing > 0)
         {
           assert (es[v].minima[0].val == es[v].minimum);
 	  assert (es[v].maxima[0].val == es[v].maximum);
@@ -1815,15 +1834,6 @@ run_examine (struct examine *cmd, struct casereader *input)
       case_unref (c);
     }
 
-  /* Remove cases on a listwise basis if requested */
-  if ( cmd->missing_pw == false)
-    input = casereader_create_filter_missing (input,
-                                              cmd->dep_vars,
-                                              cmd->n_dep_vars,
-                                              cmd->dep_excl,
-                                              NULL,
-                                              NULL);
-
   for (reader = input;
        (c = casereader_read (reader)) != NULL; case_unref (c))
     {
@@ -1836,6 +1846,10 @@ run_examine (struct examine *cmd, struct casereader *input)
     {
       summary_report (cmd, i);
 
+      const size_t n_cats =  categoricals_n_count (cmd->cats, i);
+      if (n_cats == 0)
+	continue;
+
       if (cmd->disp_extremes > 0)
         extremes_report (cmd, i);
 
diff --git a/tests/language/stats/examine.at b/tests/language/stats/examine.at
index 29dab48ff2..d4540ba45d 100644
--- a/tests/language/stats/examine.at
+++ b/tests/language/stats/examine.at
@@ -615,7 +615,12 @@ BEGIN DATA.
 .
 END DATA.
 
-EXAMINE /x PLOT=HISTOGRAM.
+EXAMINE /x 
+	PLOT=HISTOGRAM BOXPLOT NPPLOT SPREADLEVEL(1) ALL
+	/ID=x
+        /STATISTICS = DESCRIPTIVES EXTREME (5) ALL
+	/PERCENTILE=AEMPIRICAL
+	.
 ])
 AT_CHECK([pspp -o pspp.csv examine.sps], [0], [ignore])
 dnl Ignore output -- this is just a no-crash check.
-- 
2.30.2