Add propagation of badflag with .= (Ops::assgn) for sf.net bug 3543056.

PDLPorters · Mar 2, 2015 · 2193f11 · 2193f11
1 parent 255adcf
commit 2193f11
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Showing 2 changed files with 25 additions and 4 deletions.
diff --git a/Basic/Ops/ops.pd b/Basic/Ops/ops.pd
@@ -373,14 +373,26 @@ sub PDL::log10 {
 #
 pp_def(
        'assgn',
-#       HandleBad => 1,
+       HandleBad => 1,
        Pars => 'a(); [o]b();',
        Code =>
        '$b() = $a();',
-#       BadCode =>
-#       'if ( $ISBAD(a()) ) { $SETBAD(b()); } else { $b() = $a(); }',
+       BadCode =>
+       'if ( $ISBAD(a()) ) { $SETBAD(b()); } else { $b() = $a(); }',
        Doc =>
 'Plain numerical assignment. This is used to implement the ".=" operator',
+		BadDoc =>
+'If C<a> is a child piddle (e.g., the result of a slice) and bad values are generated in C<b>,
+the bad value flag is set in C<b>, but it is B<NOT> automatically propagated back to the parent of C<a>.
+The following idiom ensures that the badflag is propagated back to the parent of C<a>:
+
+ $pdl->slice(":,(1)") .= PDL::Bad_aware_func();
+ $pdl->badflag(1);
+ $pdl->check_badflag();
+
+This is unnecessary if $pdl->badflag is known to be 1 before the slice is performed.
+
+See http://pdl.perl.org/PDLdocs/BadValues.html#dataflow_of_the_badflag for details.'
 ); # pp_def assgn
 
 #pp_export_nothing(); 

diff --git a/t/ops.t b/t/ops.t
@@ -15,7 +15,7 @@ sub tapprox {
 	return $d < 0.01;
 }
 
-print "1..44\n";
+print "1..45\n";
 
 # $a0 = zeroes 3,5;
 # $b0 = xvals $a0;
@@ -156,3 +156,12 @@ $b = $a->qsorti;
 $c = $b % 3;
 ok(43,all($c->double==pdl("0 1 2 " x 5)));
 ok(44,longlong(10)%longlong(5)==0);
+
+# Check badflag propagation with .= (Ops::assgn) sf.net bug 3543056
+$a = sequence(10);
+$b = sequence(5);
+$b->inplace->setvaltobad(3);
+$a->slice('0:4') .= $b;
+$a->badflag(1);
+$a->check_badflag();
+ok(45,$a->badflag == 1 && $a->nbad == 1);