From dc9318cc16bfa8aba02cc0f364b1ca3a7cf1de9d Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Mon, 25 Oct 2010 22:52:10 -0700
Subject: [PATCH] CROSSTABS: Handle case where all cases in a crosstabulation
 are missing.

Thanks to Michel Boaventura for reporting the problem.
Bug #31260.
---
 src/language/stats/crosstabs.q    | 22 +++++++++++++++++++---
 tests/language/stats/crosstabs.at | 23 +++++++++++++++++++++++
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/src/language/stats/crosstabs.q b/src/language/stats/crosstabs.q
index be096bc4..189e7182 100644
--- a/src/language/stats/crosstabs.q
+++ b/src/language/stats/crosstabs.q
@@ -908,9 +908,7 @@ static void table_value_missing (struct crosstabs_proc *proc,
 static void delete_missing (struct pivot_table *);
 static void build_matrix (struct pivot_table *);
 
-/* Output pivot table beginning at PB and continuing until PE,
-   exclusive.  For efficiency, *MATP is a pointer to a matrix that can
-   hold *MAXROWS entries. */
+/* Output pivot table PT in the context of PROC. */
 static void
 output_pivot_table (struct crosstabs_proc *proc, struct pivot_table *pt)
 {
@@ -924,6 +922,24 @@ output_pivot_table (struct crosstabs_proc *proc, struct pivot_table *pt)
 
   enum_var_values (pt, COL_VAR, &pt->cols, &pt->n_cols, proc->descending);
 
+  if (pt->n_cols == 0)
+    {
+      struct string vars;
+      int i;
+
+      ds_init_cstr (&vars, var_get_name (pt->vars[0]));
+      for (i = 1; i < pt->n_vars; i++)
+        ds_put_format (&vars, " * %s", var_get_name (pt->vars[i]));
+
+      /* TRANSLATORS: The %s here describes a crosstabulation.  It takes the
+         form "var1 * var2 * var3 * ...".  */
+      msg (SW, _("Crosstabulation %s contained no non-missing cases."),
+           ds_cstr (&vars));
+
+      ds_destroy (&vars);
+      return;
+    }
+
   if (proc->cells)
     table = create_crosstab_table (proc, pt);
   if (proc->statistics & (1u << CRS_ST_CHISQ))
diff --git a/tests/language/stats/crosstabs.at b/tests/language/stats/crosstabs.at
index b0da517f..2657cc45 100644
--- a/tests/language/stats/crosstabs.at
+++ b/tests/language/stats/crosstabs.at
@@ -378,3 +378,26 @@ x,2.00,1.00,Total
 Total,4.0,2.0,6.0
 ]])
 AT_CLEANUP
+
+# Bug #31260.
+AT_SETUP([CROSSTABS crash when all cases missing])
+AT_DATA([crosstabs.sps], [dnl
+DATA LIST LIST NOTABLE /X1 X2.
+BEGIN DATA.
+1 1
+END DATA.
+
+MISSING VALUES x2 (1).
+
+CROSSTABS /TABLES= X1 by X2.
+])
+AT_CHECK([pspp -O format=csv crosstabs.sps], [0], [dnl
+Table: Summary.
+,Cases,,,,,
+,Valid,,Missing,,Total,
+,N,Percent,N,Percent,N,Percent
+X1 * X2,0,0.0%,1,100.0%,1,100.0%
+
+crosstabs.sps:8: warning: CROSSTABS: Crosstabulation X1 * X2 contained no non-missing cases.
+])
+AT_CLEANUP
-- 
2.30.2