dev-php/twig: fix build with USE=extension unset.

In commit 14f2ab0, I accidentally broke building with
USE="-extension".  The eclass src_prepare phase was correctly skipped
(a new change), but then afterwards it became possible for the eclass
src_configure and src_compile to fail. Now those phases are skipped
when USE="-extension", too. For consistency and for a minor
performance improvement, the eclass src_unpack phase is skipped, too.

A new revision was made because I'm not 100% certain that it wasn't
possible to install the extension with USE="-extension" before. If
it was possible, any victims would want to re-emerge twig. I have
also added an unconditional RDEPEND on "dev-lang/php" that could
have been omitted before; that would itself justify a new revision.

Gentoo-Bug: 604874

Package-Manager: portage-2.3.0

dev-php/twig/twig-1.29.0-r1.ebuild

@@ -24,15 +24,43 @@ IUSE="doc extension test"
 
 DEPEND="test? ( dev-php/phpunit )"
 
+# We always require *some* version of PHP; the eclass (conditionally)
+# requires *specific* versions.
+RDEPEND="dev-lang/php"
+
+src_unpack() {
+	# Don't make copies of the source tree if they won't be used.
+	if use extension; then
+		php-ext-source-r3_src_unpack
+	else
+		default
+	fi
+}
+
 src_prepare(){
 	# We need to call eapply_user ourselves, because it may be skipped
 	# if either the "extension" USE flag is not set, or if the user's
 	# PHP_TARGETS is essentially empty (does not contain "php5-6"). In
-	# the latter case, the eclass src_prepare does nothing.
+	# the latter case, the eclass src_prepare does nothing. We only call
+	# the eclass phase conditionally because the correct version of
+	# e.g. "phpize" may not be there unless USE=extension is set.
 	eapply_user
 	use extension && php-ext-source-r3_src_prepare
 }
 
+src_configure() {
+	# The eclass phase will try to run the ./configure script even if it
+	# doesn't exist (in contrast to the default src_configure), so we
+	# need to skip it if the eclass src_prepare (that creates said
+	# script) is not run.
+	use extension && php-ext-source-r3_src_configure
+}
+
+src_compile() {
+	# Avoids the same problem as in src_configure.
+	use extension && php-ext-source-r3_src_compile
+}
+
 src_install(){
 	use extension && php-ext-source-r3_src_install