kchmviewer: fix port for legacy systems

devel/kchmviewer/Portfile

@@ -2,10 +2,6 @@
 
 PortSystem 1.0
 
-# kchmviewer's KDE variant still requires KDE4 and will thus not be shipped for now.
-# The pure Qt variant is obtained by using QMake instead of CMake.
-PortGroup qmake5 1.0
-
 name kchmviewer
 version 7.7
 revision 1
@@ -26,19 +22,30 @@ distname ${name}-${version}
 master_sites sourceforge:project/${name}/${name}/${version}
 
 checksums rmd160 3b072a3225c5a4c796a9406232c3f696285d9aa4 \
- sha256 27cbac45c786b1718550a87e6f86010e161302b426c6396ff2a3091b913b17dd
+ sha256 27cbac45c786b1718550a87e6f86010e161302b426c6396ff2a3091b913b17dd \
+ size 345952
+
+# kchmviewer's KDE variant still requires KDE4 and will thus not be shipped for now.
+# The pure Qt variant is obtained by using QMake instead of CMake.
+if {${os.platform} ne "darwin" || ${os.major} > 11} {
+ PortGroup qmake5 1.0
+
+ # kchmviewer is transitioning to QtWebEngine, but that adaptation is not yet functional.
+ # (and WebKit is a much more appropriate choice anyway.)
+ qt5.depends_component \
+ qtwebkit
+} else {
+ # Fallback for older systems without Qt5:
+ PortGroup qmake 1.0
+
+}
 
 depends_build-append \
  port:dos2unix
 
 depends_lib-append port:libzip \
  port:chmlib
 
-# kchmviewer is transitioning to QtWebEngine, but that adaptation is not yet functional.
-# (and WebKit is a much more appropriate choice anyway.)
-qt5.depends_component \
- qtwebkit
-
 post-extract {
  # force consistent line-endings
  system -W ${worksrcpath} "find . \\\( -name \"*.cpp\" -o -name \"*.h\" -o -name \"*.pro\" \\\) -exec dos2unix '{}' \";\""
@@ -62,6 +69,9 @@ post-patch {
  ${worksrcpath}/src/src.pro
 }
 
+# zip.h: error: wrong number of arguments specified for ‘deprecated’ attribute
+compiler.blacklist-append *gcc-4.0 *gcc-4.2
+
 configure.cppflags-append -I${prefix}/lib/libzip/include
 configure.pre_args-append ${worksrcpath}/${name}.pro
 configure.args-append -recursive