[gimp-help-2/cygwin-windows-quirks] Adapt build system to Cygwin

[Ulf-D. Ehlert <ulfehlert src gnome org>]

commit af8b7029c06e1e4f6f414eb5b82cc6842951d522
Author: Ulf-D. Ehlert <ulfehlert svn gnome org>
Date:   Tue Jun 23 10:30:14 2009 +0200

    Adapt build system to Cygwin
    
    * configure.ac: identify Cygwin with autoconf macro
    * Makefile.am: under Cygwin, use hardlinks rather than symlinks
      for making image file links

 Makefile.am  |   24 +++++++++++++++++++++---
 configure.ac |   11 +++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index c0c25b4..93c2487 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -469,7 +469,7 @@ include $(foreach LANG,$(PO_LANGS),xml/$(LANG)/.deps.mk)
 # HIDE FROM AUTOMAKE #$(foreach LANG,$(PO_LANGS),$(eval $(call MAKE_XML_RULES,$(LANG))))
 
 # TODO: test new image files structure;
-#   how to ensure that $@ is up-to-date without forcing
+#   problem: how to ensure that $@ is up-to-date without forcing
 #   rebuild (which will also force e.g. html-% to be rebuilt 
 #   -- use (~1500) image files as prerequisites?
 xml/%/images: FORCE
@@ -478,9 +478,16 @@ xml/%/images: FORCE
 	$(cmd) if test -d $@; then rm -rf $@/*; fi
 	$(cmd) test -d $@ || $(MKDIR_P) $@
 	$(cmd) $(echo_n) "*** Copying images ($*) ..."
+if CYGWIN
+# Cygwin
 	$(cmd) perl $(srcdir)/tools/make_image_links.pl -v \
-	           $(srcdir)/images/common $(srcdir)/images/C \
-		   xml/$*
+	           --mode=hardlink,copy \
+	           $(srcdir)/images/{common,C} $@
+else
+# Default (non-Cygwin)
+	$(cmd) perl $(srcdir)/tools/make_image_links.pl -v \
+	           $(srcdir)/images/{common,C} $@
+endif
 
 # Special case: en
 
@@ -576,9 +583,20 @@ html/%/index.html: xml/% $(HTML_STYLESHEETS) html/%/images
 	done
 
 # TODO: check/enhance new image files structure
+if CYGWIN
+# Cygwin
+html/%/images: FORCE
+	$(cmd) test -h $@ && rm -f $@
+	$(cmd) test -d $@ && rm -rf $@/* || $(MKDIR_P) $@
+	$(cmd) perl $(srcdir)/tools/make_image_links.pl -v \
+	           --mode=hardlink,copy \
+	           $(srcdir)/images/{common,C} $@
+else
+# Default (non-Cygwin)
 html/%/images: xml/%/images
 	$(cmd) test -d html/$* || $(MKDIR_P) html/$*
 	$(cmd) test -e $@ || $(LN_S) ../../$< $@
+endif
 
 # The xrefs file is a side effect of the HTML build
 html/%/gimp-xrefs.xml: html/%/index.html
diff --git a/configure.ac b/configure.ac
index c9ad58e..e714e61 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,6 +12,17 @@ m4_define([help_version], [help_major_version.help_minor_version.help_micro_vers
 
 AC_INIT([GIMP-Help], [help_version])
 
+# Apparently this macro must be called before "AM_INIT_AUTOMAKE"
+AC_CANONICAL_BUILD
+case $build_os in
+  *cygwin*) IS_CYGWIN=yes;;
+         *) IS_CYGWIN=no;;
+esac
+# for use in Makefile.am
+AM_CONDITIONAL(CYGWIN, test $IS_CYGWIN = yes)
+# for use in Makefile
+#AC_SUBST(IS_CYGWIN)
+
 AC_CONFIG_SRCDIR([src/gimp.xml])
 
 AM_INIT_AUTOMAKE([1.6 dist-bzip2 -Wall -Wno-portability])