2 files changed, 45 insertions, 0 deletions
diff --git a/academic/root/root.SlackBuild b/academic/root/root.SlackBuild
index aaed68d9ef44..0a182993d8cb 100644
--- a/academic/root/root.SlackBuild
+++ b/academic/root/root.SlackBuild
@@ -98,6 +98,9 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 600 -o -perm 444 -o -perm 440 -o -perm 400 \) \
  -exec chmod 644 {} \;
 
+# Fix building with gsl-2.1
+patch -p1 < $CWD/root_gsl2.patch
+
 # Make sure we use system libs and headers
 rm -r graf3d/ftgl/{inc,src} || die
 rm -r graf2d/freetype/src || die
diff --git a/academic/root/root_gsl2.patch b/academic/root/root_gsl2.patch
new file mode 100644
index 000000000000..8f049d7e03bb
--- /dev/null
+++ b/academic/root/root_gsl2.patch
@@ -0,0 +1,42 @@
+diff -u -r root/math/mathmore/src/GSLMultiFit.h root-patched/math/mathmore/src/GSLMultiFit.h
+--- root/math/mathmore/src/GSLMultiFit.h	2015-06-23 16:56:20.000000000 +0100
++++ root-patched/math/mathmore/src/GSLMultiFit.h	2015-11-18 22:30:54.300681289 +0000
+@@ -32,6 +32,7 @@
+ #include "gsl/gsl_multifit_nlin.h"
+ #include "gsl/gsl_blas.h"
+ #include "GSLMultiFitFunctionWrapper.h"
++#include <gsl/gsl_version.h>
+ 
+ #include "Math/IFunction.h"
+ #include <string>
+@@ -139,7 +140,14 @@
+    /// gradient value at the minimum 
+    const double * Gradient() const { 
+       if (fSolver == 0) return 0; 
+-      gsl_multifit_gradient(fSolver->J, fSolver->f,fVec);       
++#if GSL_MAJOR_VERSION >=2
++      gsl_matrix *J=gsl_matrix_alloc(fSolver->fdf->n, fSolver->fdf->p);
++      gsl_multifit_fdfsolver_jac (fSolver, J);
++      gsl_multifit_gradient(J, fSolver->f, fVec);
++      gsl_matrix_free(J);
++#else
++      gsl_multifit_gradient(fSolver->J, fSolver->f, fVec);
++#endif
+       return fVec->data; 
+    }
+ 
+@@ -150,7 +158,14 @@
+       unsigned int npar = fSolver->fdf->p; 
+       fCov = gsl_matrix_alloc( npar, npar ); 
+       static double kEpsrel = 0.0001;
++#if GSL_MAJOR_VERSION >=2
++      gsl_matrix *J=gsl_matrix_alloc(fSolver->fdf->n, fSolver->fdf->p);
++      gsl_multifit_fdfsolver_jac (fSolver, J);
++      int ret = gsl_multifit_covar(J, kEpsrel, fCov);
++      gsl_matrix_free(J);
++#else
+       int ret = gsl_multifit_covar(fSolver->J, kEpsrel, fCov);
++#endif
+       if (ret != GSL_SUCCESS) return 0; 
+       return fCov->data; 
+    }