* libxml2 / libxslt: provide a setup hook that prevents xmllint and

xsltproc from downloading DTDs from the network, which is impure.
  This caused a lot of problems with Gnome builds in the build farm,
  because those downloads are slow and would sometimes fail.

  The setup hook also sets up $XML_CATALOG_FILES.

svn path=/nixpkgs/trunk/; revision=9471

pkgs/development/libraries/libxml2/setup-hook.sh

@@ -0,0 +1,25 @@
+addXMLCatalogs () {
+    if test -d $1/xml/dtd; then
+        for i in $(find $1/xml/dtd -name catalog.xml); do
+            export XML_CATALOG_FILES="$XML_CATALOG_FILES $i"
+        done
+    fi
+}
+
+if test -z "$libxmlHookDone"; then
+    libxmlHookDone=1
+
+    # Set http_proxy and ftp_proxy to a invalid host to prevent
+    # xmllint and xsltproc from trying to download DTDs from the
+    # network even when --nonet is not given.  That would be impure.
+    # (Note that .invalid is a reserved domain guaranteed not to
+    # work.)
+    export http_proxy=http://nodtd.invalid/
+    export ftp_proxy=http://nodtd.invalid/
+
+    # Set up XML_CATALOG_FILES.  An empty initial value prevents
+    # xmllint and xsltproc from looking in /etc/xml/catalog.
+    export XML_CATALOG_FILES
+    if test -z "$XML_CATALOG_FILES"; then XML_CATALOG_FILES=" "; fi
+    envHooks=(${envHooks[@]} addXMLCatalogs)
+fi