[matio] fix build on big endian platforms

[Dan Horák]

commit 4d7b38a65b814314fde145bc3593c911a0a795c1
Author: Dan Horák <dan at danny.cz>
Date:   Wed Jan 9 19:23:41 2013 +0100

    fix build on big endian platforms

 matio-1.5.0-big-endian.patch |   54 ++++++++++++++++++++++++++++++++++++++++++
 matio.spec                   |    7 ++++-
 2 files changed, 60 insertions(+), 1 deletions(-)
---
diff --git a/matio-1.5.0-big-endian.patch b/matio-1.5.0-big-endian.patch
new file mode 100644
index 0000000..53f5032
--- /dev/null
+++ b/matio-1.5.0-big-endian.patch
@@ -0,0 +1,54 @@
+From: Christopher Hulbert <chulbe2lsu at users.sourceforge.net>
+Date: Thu, 20 Dec 2012 17:29:04 +0000 (-0500)
+Subject: Fix endian check for v4 MAT files and big-endian systems
+X-Git-Url: http://matio.git.sourceforge.net/git/gitweb.cgi?p=matio%2Fmatio;a=commitdiff_plain;h=3b91a84c6f6ab5e401df18b5b0589bedce42df6a;hp=09f5c87438a5883361b38cc98b4848acfcb65d97
+
+Fix endian check for v4 MAT files and big-endian systems
+
+* src/mat4.c (Mat_VarReadNextInfo4): Check endianness of host computer and
+      compare to the M part of the variable type to determine if
+      byteswapping is required
+---
+
+diff --git a/src/mat4.c b/src/mat4.c
+index bf2aaae..b1d7194 100644
+--- a/src/mat4.c
++++ b/src/mat4.c
+@@ -193,6 +193,10 @@ Mat_VarReadNextInfo4(mat_t *mat)
+     long      nBytes;
+     size_t    err;
+     matvar_t *matvar = NULL;
++    union {
++        mat_uint32_t u;
++        mat_uint8_t  c[4];
++    } endian;
+ 
+     if ( mat == NULL || mat->fp == NULL )
+         return NULL;
+@@ -208,6 +212,8 @@ Mat_VarReadNextInfo4(mat_t *mat)
+         return NULL;
+     }
+ 
++    endian.u = 0x01020304;
++
+     /* See if MOPT may need byteswapping */
+     if ( tmp < 0 || tmp > 4052 ) {
+         if ( Mat_int32Swap(&tmp) > 4052 ) {
+@@ -224,7 +230,16 @@ Mat_VarReadNextInfo4(mat_t *mat)
+     tmp -= data_type*10;
+     class_type = floor(tmp);
+ 
+-    mat->byteswap = (M == 1) ? 1 : 0;
++    switch ( M ) {
++        case 0:
++            /* IEEE little endian */
++            mat->byteswap = (endian.c[0] != 4);
++            break;
++        case 1:
++            /* IEEE big endian */
++            mat->byteswap = (endian.c[0] != 1);
++            break;
++    }
+     /* Convert the V4 data type */
+     switch ( data_type ) {
+         case 0:
diff --git a/matio.spec b/matio.spec
index 046192e..857756d 100644
--- a/matio.spec
+++ b/matio.spec
@@ -1,12 +1,13 @@
 Name:           matio
 Version:        1.5.0
-Release:        4%{?dist}
+Release:        5%{?dist}
 Summary:        Library for reading/writing Matlab MAT files
 
 Group:          System Environment/Libraries
 License:        BSD
 URL:            http://sourceforge.net/projects/matio
 Source0:        http://downloads.sourceforge.net/matio/matio-%{version}.tar.gz
+Patch0:         %{name}-1.5.0-big-endian.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
 BuildRequires:  doxygen
@@ -37,6 +38,7 @@ developing applications that use %{name}.
 
 %prep
 %setup -q
+%patch0 -p1 -b .big-endian
 
 
 %build
@@ -94,6 +96,9 @@ rm -rf $RPM_BUILD_ROOT
 
 
 %changelog
+* Wed Jan 09 2013 Dan Horák <dan[at]danny.cz> - 1.5.0-5
+- fix build on big endian platforms
+
 * Wed Dec 05 2012 Orion Poplawski <orion at cora.nwra.com> - 1.5.0-4
 - Rebuild for hdf5 1.8.10