From bug-request at octave dot org Thu Dec  8 13:55:37 2005
Subject: Octave segfaults on a valid command line
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: "Michael Smolsky" <sitrash at email dot com>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Thu, 8 Dec 2005 14:55:30 -0500

| Thanks for maintaining a great product.

Please think of Octave as a community project that is developed and
enjoyed by all its users rather than a product (which seems to imply that it
is something produced by others to be consumed by users).

| Octave crashes on the following command line:
| 
| clear,u=[1,2,3];v=find(u>100);for i=u(v).',i,end

I'm not able to reproduce the crash in the current recommended
version (2.1.72) or a copy built from the current CVS sources.

OTOH, theere seems to be a compatibility problem such that

  for i = zeros (0, N), i, endfor

doesn't do the right thing in Octave (it should assign [](0x1) to i
and go through the loop N times.  For that problem, please try the
following patch.  These changes are relative to the current 2.1.x
branch in the CVS archive.  A similar change will be checked in to the
main CVS branch (2.9.x) soon.

Thanks,

jwe


src/ChangeLog

2005-12-08  John W. Eaton  <jwe at octave dot org>

	* pt-loop.cc (DO_ND_LOOP): Simplify.  New arg, TYPE.  Change all uses.
	(simple_for_loop_command::eval): Correctly handle N-d numeric and
	cell arrays when only the first dimension is 0.


Index: src/pt-loop.cc
===================================================================
RCS file: /usr/local/cvsroot/octave/src/pt-loop.cc,v
retrieving revision 1.26.2.2
diff -u -r1.26.2.2 pt-loop.cc
--- src/pt-loop.cc	26 Apr 2005 19:43:59 -0000	1.26.2.2
+++ src/pt-loop.cc	8 Dec 2005 19:50:53 -0000
 at @ -242,20 +242,25 @@
     } \
   while (0)
 
-#define DO_ND_LOOP(arg) \
+#define DO_ND_LOOP(TYPE, ARG) \
   do \
     { \
-      int ndims = dv.length (); \
-      Array<idx_vector> idx; \
-      int steps = dv.numel () / dv (0); \
-      idx.resize (ndims, idx_vector (1)); \
-      idx (0) = idx_vector (':'); \
+      int steps = dv(1); \
  \
       for (int i = 0; i < steps; i++) \
 	{ \
 	  MAYBE_DO_BREAKPOINT; \
  \
-	  octave_value val (arg.index(idx)); \
+          TYPE tmp; \
+ \
+          int nr = ARG.rows (); \
+ \
+	  tmp.resize (dim_vector (nr, 1)); \
+ \
+	  for (int j = 0; j < nr; j++) \
+	    tmp.xelem (j) = ARG.xelem (j, i); \
+ \
+          octave_value val (tmp); \
  \
 	  bool quit = false; \
  \
 at @ -265,14 +270,6 @@
 	  if (quit) \
 	    break; \
  \
-	  for (int j = 1; j < ndims; j++) \
-	    { \
-	      idx(j) = idx_vector (idx(j)(0) + 2); \
-	      if (idx(j)(0) < dv(j)) \
-		break; \
-	      else \
-		idx(j) = idx_vector (1); \
-	    } \
 	} \
     } \
   while (0)
 at @ -386,12 +383,27 @@
 	if (error_state)
 	  goto cleanup;
 
-	if (dv.numel () > 0)
+	// XXX FIXME XXX -- maybe we need a function for this?
+	int ndims = dv.length ();
+	for (int i = 2; i < ndims; i++)
+	  dv(1) *= dv(i);
+
+	if (dv(1) > 0)
 	  {
 	    if (rhs.is_real_type ())
-	      DO_ND_LOOP(m_tmp);
+	      {
+		if (ndims > 2)
+		  m_tmp = m_tmp.reshape (dv);
+
+		DO_ND_LOOP(NDArray, m_tmp);
+	      }
 	    else
-	      DO_ND_LOOP(cm_tmp);
+	      {
+		if (ndims > 2)
+		  cm_tmp = cm_tmp.reshape (dv);
+
+		DO_ND_LOOP(ComplexNDArray, cm_tmp);
+	      }
 	  }
       }
     else if (rhs.is_map ())
 at @ -423,8 +435,18 @@
 
 	dim_vector dv = c_tmp.dims ();
 
-	if (dv.numel () > 0)
-	  DO_ND_LOOP(c_tmp);
+	// XXX FIXME XXX -- maybe we need a function for this?
+	int ndims = dv.length ();
+	for (int i = 2; i < ndims; i++)
+	  dv(1) *= dv(i);
+
+	if (dv(1) > 0)
+	  {
+	    if (ndims > 2)
+	      c_tmp = c_tmp.reshape (dv);
+
+	    DO_ND_LOOP(Cell, c_tmp);
+	  }
       }
     else
       {




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