Fall back to using pkg-config if cppunit-config is not found

Latest versions of CppUnit removed cppunit-config and use pkg-config instead,
so try the latter if the former is not found to detect CppUnit under Fedora 24
for example.

Closes #17387.

configure

@@ -1398,7 +1398,9 @@ WEBKIT_LIBS
 CAIRO_CFLAGS
 CAIRO_LIBS
 GST_CFLAGS
-GST_LIBS'
+GST_LIBS
+CPPUNIT_CFLAGS
+CPPUNIT_LIBS'
 ac_subdirs_all='src/tiff
 src/expat'
 
@@ -2390,6 +2392,10 @@ Some influential environment variables:
   CAIRO_LIBS  linker flags for CAIRO, overriding pkg-config
   GST_CFLAGS  C compiler flags for GST, overriding pkg-config
   GST_LIBS    linker flags for GST, overriding pkg-config
+  CPPUNIT_CFLAGS
+              C compiler flags for CPPUNIT, overriding pkg-config
+  CPPUNIT_LIBS
+              linker flags for CPPUNIT, overriding pkg-config
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -39183,7 +39189,82 @@ $as_echo "no" >&6; }
   else
      CPPUNIT_CFLAGS=""
      CPPUNIT_LIBS=""
-     :
+
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for CPPUNIT" >&5
+$as_echo_n "checking for CPPUNIT... " >&6; }
+
+if test -n "$PKG_CONFIG"; then
+    if test -n "$CPPUNIT_CFLAGS"; then
+        pkg_cv_CPPUNIT_CFLAGS="$CPPUNIT_CFLAGS"
+    else
+        if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"cppunit >= 1.8.0\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "cppunit >= 1.8.0") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_CPPUNIT_CFLAGS=`$PKG_CONFIG --cflags "cppunit >= 1.8.0" 2>/dev/null`
+else
+  pkg_failed=yes
+fi
+    fi
+else
+	pkg_failed=untried
+fi
+if test -n "$PKG_CONFIG"; then
+    if test -n "$CPPUNIT_LIBS"; then
+        pkg_cv_CPPUNIT_LIBS="$CPPUNIT_LIBS"
+    else
+        if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"cppunit >= 1.8.0\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "cppunit >= 1.8.0") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_CPPUNIT_LIBS=`$PKG_CONFIG --libs "cppunit >= 1.8.0" 2>/dev/null`
+else
+  pkg_failed=yes
+fi
+    fi
+else
+	pkg_failed=untried
+fi
+
+
+
+if test $pkg_failed = yes; then
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        CPPUNIT_PKG_ERRORS=`$PKG_CONFIG --short-errors --errors-to-stdout --print-errors "cppunit >= 1.8.0"`
+        else
+	        CPPUNIT_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "cppunit >= 1.8.0"`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$CPPUNIT_PKG_ERRORS" >&5
+
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cppunit not found" >&5
+$as_echo "$as_me: WARNING: cppunit not found" >&2;}
+
+elif test $pkg_failed = untried; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: cppunit not found" >&5
+$as_echo "$as_me: WARNING: cppunit not found" >&2;}
+
+else
+	CPPUNIT_CFLAGS=$pkg_cv_CPPUNIT_CFLAGS
+	CPPUNIT_LIBS=$pkg_cv_CPPUNIT_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+	SUBDIRS="$SUBDIRS tests"
+fi
+
+
   fi
 
 

configure.in

@@ -8040,7 +8040,15 @@ else
     SUBDIRS="samples utils"
 fi
 dnl Add tests to the list of subdirs if cppunit 1.8.0+ is detected
-AM_PATH_CPPUNIT(1.8.0, [SUBDIRS="$SUBDIRS tests"])
+AM_PATH_CPPUNIT(1.8.0,
+    [SUBDIRS="$SUBDIRS tests"],
+    [
+        PKG_CHECK_MODULES(CPPUNIT, [cppunit >= 1.8.0],
+            [SUBDIRS="$SUBDIRS tests"],
+            [AC_MSG_WARN([cppunit not found])]
+        )
+    ]
+)
 
 for subdir in $SUBDIRS; do
     if test -d ${srcdir}/${subdir} ; then