sys-file-reader: Don't warn if compression bias field is 0.

[pspp-builds.git] / src / data / sys-file-reader.c

diff --git a/src/data/sys-file-reader.c b/src/data/sys-file-reader.c
index e8349abf19077bf2c7751853f4d82d8f9c21bd53..fe7b53342128087687d39e74d46721b1cb5917ed 100644 (file)
--- a/src/data/sys-file-reader.c
+++ b/src/data/sys-file-reader.c
@@ -425,9 +425,21 @@ read_header (struct sfm_reader *r, struct dictionary *dict,
   read_bytes (r, raw_bias, sizeof raw_bias);
   if (float_identify (100.0, raw_bias, sizeof raw_bias, &r->float_format) == 0)
     {
-      sys_warn (r, _("Compression bias is not the usual "
-                     "value of 100, or system file uses unrecognized "
-                     "floating-point format."));
+      uint8_t zero_bias[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+
+      if (memcmp (raw_bias, zero_bias, 8))
+        sys_warn (r, _("Compression bias is not the usual "
+                       "value of 100, or system file uses unrecognized "
+                       "floating-point format."));
+      else
+        {
+          /* Some software is known to write all-zeros to this
+             field.  Such software also writes floating-point
+             numbers in the format that we expect by default
+             (it seems that all software most likely does, in
+             reality), so don't warn in this case. */
+        }
+
       if (r->integer_format == INTEGER_MSB_FIRST)
         r->float_format = FLOAT_IEEE_DOUBLE_BE;
       else