Fix FTBFS on i686-linux due to rounding issue (see references).

Fixes Guix bug #22049 (see below).

Copied from Debian.

Source:
https://sources.debian.net/src/ilmbase/2.2.0-11/debian/patches/testBoxAlgo.patch/
https://sources.debian.net/src/ilmbase/2.2.0-11/debian/patches/testBox.patch/

References:
https://lists.nongnu.org/archive/html/openexr-devel/2015-12/msg00001.html
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22049
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=815712
https://anonscm.debian.org/cgit/pkg-phototools/ilmbase.git/commit/?id=ab28bb45cdad8adc32e345b777ab8e692b1d9a9c

---

Subject: testBoxAlgo: allow fuzzy match of b12 == b2
From: Steven Chamberlain <steven@pyro.eu.org>
Date: Wed, 24 Feb 2016 01:04:11 +0000

Also fix a pre-existing typo.

--- a/IlmBase/ImathTest/testBoxAlgo.cpp
+++ b/IlmBase/ImathTest/testBoxAlgo.cpp
@@ -886,10 +886,11 @@ boxMatrixTransform ()
 
     assert (approximatelyEqual (b2.min, b4.min, e));
     assert (approximatelyEqual (b2.max, b4.max, e));
-    assert (approximatelyEqual (b3.max, b4.max, e));
+    assert (approximatelyEqual (b3.min, b4.min, e));
     assert (approximatelyEqual (b3.max, b4.max, e));
 
-    assert (b21 == b2);
+    assert (approximatelyEqual (b2.min, b21.min, e));
+    assert (approximatelyEqual (b2.max, b21.max, e));
     assert (b31 == b3);
 
     M[0][3] = 1;

---

Subject: testBox: allow fuzzy comparison of floats, doubles
From: Steven Chamberlain <steven@pyro.eu.org>
Date: Wed, 24 Feb 2016 01:10:11 +0000

Allow for inexact values, as long as the error is smaller than the
epsilon of the data type.

On 32-bit x86, allow even greater discrepency at double
precision, due to possible double-rounding.  See
https://lists.nongnu.org/archive/html/openexr-devel/2015-12/msg00001.html

--- a/IlmBase/ImathTest/testBox.cpp
+++ b/IlmBase/ImathTest/testBox.cpp
@@ -47,6 +47,58 @@ using namespace IMATH_INTERNAL_NAMESPACE
 
 namespace {
 
+template <class T>
+bool
+approximatelyEqual (const T &p1, const T &p2)
+{
+	/* int and short should be exact */
+	return (p1 == p2);
+}
+
+bool
+approximatelyEqual (const Vec2<float> &p1, const Vec2<float> &p2)
+{
+    float e = limits<float>::epsilon();
+    float m = 0;
+
+    for (int i = 0; i < 2; ++i)
+    {
+	m = max (m, abs (p1[i]));
+	m = max (m, abs (p2[i]));
+    }
+
+    for (int i = 0; i < 2; ++i)
+	if (!equalWithAbsError (p1[i], p2[i], m * e))
+	    return false;
+
+    return true;
+}
+
+bool
+approximatelyEqual (const Vec2<double> &p1, const Vec2<double> &p2)
+{
+#if defined(__i386__) || defined(_M_IX86)
+    /* double-rounding on 32-bit x86 may cause larger error:
+       use epsilon of float rather than double */
+    double e = limits<float>::epsilon();
+#else
+    double e = limits<double>::epsilon();
+#endif
+    double m = 0;
+
+    for (int i = 0; i < 2; ++i)
+    {
+	m = max (m, abs (p1[i]));
+	m = max (m, abs (p2[i]));
+    }
+
+    for (int i = 0; i < 2; ++i)
+	if (!equalWithAbsError (p1[i], p2[i], m * e))
+	    return false;
+
+    return true;
+}
+
 //
 // Test case generation utility - create a vector of IMATH_INTERNAL_NAMESPACE::Vec{2,3,4}
 // with all permutations of integers 1..T::dimensions().
@@ -250,7 +302,8 @@ testExtendByPoint(const char *type)
                               
         IMATH_INTERNAL_NAMESPACE::Box<T> b;
         b.extendBy(p);
-        assert(b.min == p && b.max == p);
+        assert (approximatelyEqual (b.min, p));
+        assert (approximatelyEqual (b.max, p));
     }
 
     //
@@ -283,7 +336,8 @@ testExtendByPoint(const char *type)
 
             b.extendBy(p);
 
-            assert(b.min == min && b.max == max);
+            assert (approximatelyEqual (b.min, min));
+            assert (approximatelyEqual (b.max, max));
         }
     }
 }
@@ -358,7 +412,8 @@ testExtendByBox(const char *type)
             }
             b.extendBy(IMATH_INTERNAL_NAMESPACE::Box<T>(p0, p1));
 
-            assert(b.min == min && b.max == max);
+            assert (approximatelyEqual (b.min, min));
+            assert (approximatelyEqual (b.max, max));
         }
     }
 }
</td></tr>
<tr><td><span title='2022-05-31 14:52:30 -0400'>2022-05-31</span></td><td><a href='/guix/commit/gnu/packages/iso-codes.scm?id=0082e6523fe729a462ea1e1c9f0d081cfda5c27e'>gnu: Remove python2-iso639.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/iso-codes.scm (python2-iso639): Delete variable.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-05-31 14:52:30 -0400'>2022-05-31</span></td><td><a href='/guix/commit/gnu/packages/iso-codes.scm?id=f2a579f8cb90313e73a40d7317b835c0fe29ea3e'>gnu: Remove python2-iso3166.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/iso-codes.scm (python2-iso3166): Delete variable.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-09-20 11:15:06 +0000'>2021-09-20</span></td><td><a href='/guix/commit/gnu/packages/iso-codes.scm?id=c170e9b75fbda901aaf46d3b8e09975cb9b422bb'>gnu: iso-codes: Move inputs to native-inputs when cross-compiling.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/iso-codes.scm
  (iso-codes)[inputs]: Move "gettext", "perl" and "python" to ...
  (iso-codes)[native-inputs]: ... here when cross-compiling.
</span></span></td><td>Maxime Devos</td></tr>
<tr><td><span title='2020-11-09 22:08:10 +0100'>2020-11-09</span></td><td><a href='/guix/commit/gnu/packages/iso-codes.scm?id=486512dcec484e0f6903e288a2eb1bb15ac585bb'>gnu: iso-codes: Update to 4.5.0.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/iso-codes.scm (iso-codes): Update to 4.5.0.
</span></span></td><td>Marius Bakke</td></tr>