From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sun, 4 May 2014 10:10:04 +0000 (+0200)
Subject: isl_Polyhedron_Reduced_Basis: avoid double free of barvinok_options
X-Git-Tag: barvinok-0.38~57
X-Git-Url: https://repo.or.cz/w/barvinok.git/commitdiff_plain/a488776044362891383dd2ba34f9d0392c1f53c0

isl_Polyhedron_Reduced_Basis: avoid double free of barvinok_options

In 6702a6a (avoid use of isl_ctx internals, Wed Mar 16 16:25:11 2011 +0100),
isl_Polyhedron_Reduced_Basis was changed to update
options->isl->gbr_only_first and the to pass the barvinok_options
to isl_ctx_alloc_with_options.  This will make the resuling isl_ctx
own the barvinok_options, which are then also freed when the isl_ctx
is freed, even though it may and in fact is reused in the very
same function after ths isl_ctx is freed.  Apparently, this change
was never tested.

In f387b45 (update isl for hiding of isl_options,
Fri Nov 11 11:33:25 2011 +0100), the function was further changed
to update the gbr_only_first isl option after the isl_ctx is created.
There is therefore no longer any need to pass the barvinok_options
to isl_ctx_alloc_with_options and we can simply call isl_ctx_alloc instead.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---

diff --git a/basis_reduction.c b/basis_reduction.c
index 359346e..c1c185f 100644
--- a/basis_reduction.c
+++ b/basis_reduction.c
@@ -33,12 +33,10 @@ Matrix *isl_Polyhedron_Reduced_Basis(Polyhedron *P,
 	isl_basic_set *bset;
 	isl_mat *basis;
 	Matrix *M;
-	int isl_gbr_only_first;
 
-	ctx = isl_ctx_alloc_with_options(&barvinok_options_args, options);
+	ctx = isl_ctx_alloc();
 	assert(ctx);
 
-	isl_gbr_only_first = isl_options_get_gbr_only_first(ctx);
 	isl_options_set_gbr_only_first(ctx, options->gbr_only_first);
 
 	dim = isl_space_set_alloc(ctx, 0, nvar);
@@ -60,8 +58,6 @@ Matrix *isl_Polyhedron_Reduced_Basis(Polyhedron *P,
 
 	isl_ctx_free(ctx);
 
-	isl_options_set_gbr_only_first(ctx, isl_gbr_only_first);
-
 	return M;
 }
 
diff --git a/testlib.cc b/testlib.cc
index 045772d..6a53e90 100644
--- a/testlib.cc
+++ b/testlib.cc
@@ -3,6 +3,7 @@
 #include <barvinok/barvinok.h>
 #include <barvinok/set.h>
 #include <barvinok/options.h>
+#include <barvinok/basis_reduction.h>
 #include <barvinok/evalue.h>
 #include <barvinok/util.h>
 #include "conversion.h"
@@ -750,6 +751,35 @@ static int test_laurent(struct barvinok_options *options)
     return 0;
 }
 
+/* Check that Polyhedron_Reduced_Basis produces a result
+ * of the expected dimensions (without crashing).
+ */
+static int test_basis_reduction(struct barvinok_options *options)
+{
+    Matrix *M;
+    Polyhedron *P;
+
+    M = matrix_read_from_str(
+	"4 4\n"
+	"1    1    0    0 \n"
+	"1    0    1    0 \n"
+	"1   -1    0    1 \n"
+	"1    0   -1    1 \n");
+    P = Constraints2Polyhedron(M, options->MaxRays);
+    Matrix_Free(M);
+
+    M = Polyhedron_Reduced_Basis(P, options);
+
+    assert(M);
+    assert(M->NbRows == 2);
+    assert(M->NbColumns == 2);
+
+    Polyhedron_Free(P);
+    Matrix_Free(M);
+
+    return 0;
+}
+
 int main(int argc, char **argv)
 {
     struct barvinok_options *options = barvinok_options_new_with_defaults();
@@ -770,5 +800,6 @@ int main(int argc, char **argv)
     test_ilp(options);
     test_hull(options);
     test_laurent(options);
+    test_basis_reduction(options);
     barvinok_options_free(options);
 }