From: Ben Pfaff <blp@cs.stanford.edu>
Date: Sun, 16 Feb 2014 07:06:13 +0000 (-0800)
Subject: pspp-dump-sav: More gracefully handle empty multiple response sets.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bdf3609794a1f7bea432415f7466b85a069f8b0c;hp=41a0546e577009ef8b8eac45793968d7519ca5cf;p=pspp

pspp-dump-sav: More gracefully handle empty multiple response sets.

Some multiple response sets have no variables, although I don't know why,
and pspp-dump-sav is more useful if it doesn't stop reading when it arrives
at one.
---

diff --git a/doc/dev/system-file-format.texi b/doc/dev/system-file-format.texi
index be6433b9a0..2d57673308 100644
--- a/doc/dev/system-file-format.texi
+++ b/doc/dev/system-file-format.texi
@@ -785,6 +785,12 @@ A space.
 The short names of the variables in the set, converted to lowercase,
 each separated from the previous by a single space.
 
+Even though a multiple response set must have at least two variables,
+some system files contain multiple response sets with no variables at
+all.  The source and meaning of these multiple response sets is
+unknown.  (Perhaps they arise from creating a multiple response set
+then deleting all the variables that it contains?)
+
 @item
 One line feed (byte 0x0a).  Sometimes multiple, even hundreds, of line
 feeds are present.
diff --git a/src/data/sys-file-reader.c b/src/data/sys-file-reader.c
index b7c5984466..abaab6f25d 100644
--- a/src/data/sys-file-reader.c
+++ b/src/data/sys-file-reader.c
@@ -1495,10 +1495,11 @@ parse_mrsets (struct sfm_reader *r, const struct sfm_extension_record *record,
           raw_var_name = text_get_token (text, ss_cstr (" \n"), &delimiter);
           if (raw_var_name == NULL)
             {
-              sys_warn (r, record->pos,
-                        _("Missing new-line parsing variable names "
-                          "at offset %zu in MRSETS record."),
-                        text_pos (text));
+              if (delimiter != '\n')
+                sys_warn (r, record->pos,
+                          _("Missing new-line parsing variable names "
+                            "at offset %zu in MRSETS record."),
+                          text_pos (text));
               break;
             }
           var_name = recode_string ("UTF-8", r->encoding, raw_var_name, -1);
diff --git a/tests/data/sys-file-reader.at b/tests/data/sys-file-reader.at
index 3c29a33bba..26ac6431db 100644
--- a/tests/data/sys-file-reader.at
+++ b/tests/data/sys-file-reader.at
@@ -2872,7 +2872,7 @@ warning: `sys-file.sav' near offset 0xd8: MRSET $a has only 1 variables.
 done
 AT_CLEANUP
 
-AT_SETUP([only one variable in mrset])
+AT_SETUP([zero or one variable in mrset])
 AT_KEYWORDS([sack synthetic system file negative multiple response])
 AT_DATA([sys-file.sack], [dnl
 dnl File header.
@@ -2883,13 +2883,13 @@ dnl Numeric variable, no label or missing values.
 2; 0; 0; 0; 0x050800 *2; s8 "NUM1";
 
 dnl Multiple response sets.
-7; 7; 1; COUNT("$a=C 0  NUM1"; i8 10);
+7; 7; 1; COUNT("$a=C 0  NUM1"; i8 10; "$b=C 0  "; i8 10);
 
 999; 0;
 ])
 for variant in \
-	"be 3a891e0a467afb3d622629c70f329ada" \
-	"le 432998ec08370510411af4f5207c015e"
+	"be d94549fece75560fe5b47f32713b63a1" \
+	"le 63028521d460df9e998b40a75a93c330"
 do
   set $variant
   AT_CHECK_UNQUOTED([sack --$[1] sys-file.sack > sys-file.sav], [0], [], [$[2]
@@ -2898,6 +2898,8 @@ do
 ])
   AT_CHECK([pspp -O format=csv sys-file.sps], [0], [dnl
 warning: `sys-file.sav' near offset 0xd8: MRSET $a has only 1 variables.
+
+warning: `sys-file.sav' near offset 0xd8: MRSET $b has only 0 variables.
 ])
 done
 AT_CLEANUP
diff --git a/utilities/pspp-dump-sav.c b/utilities/pspp-dump-sav.c
index c31c02a927..879c3748d3 100644
--- a/utilities/pspp-dump-sav.c
+++ b/utilities/pspp-dump-sav.c
@@ -832,12 +832,6 @@ read_mrsets (struct sfm_reader *r, size_t size, size_t count)
         break;
 
       variables = text_tokenize (text, '\n');
-      if (variables == NULL)
-        {
-          sys_warn (r, "missing variable names following label "
-                    "at offset %zu in mrsets record", text_pos (text));
-          break;
-        }
 
       printf ("\t\"%s\": multiple %s set",
               name, type == MRSET_MC ? "category" : "dichotomy");
@@ -849,7 +843,10 @@ read_mrsets (struct sfm_reader *r, size_t size, size_t count)
         printf (", label \"%s\"", label);
       if (label_from_var_label)
         printf (", label from variable label");
-      printf(", variables \"%s\"\n", variables);
+      if (variables != NULL)
+        printf(", variables \"%s\"\n", variables);
+      else
+        printf(", no variables\n");
     }
   close_text_record (text);
 }