Contrib: new --no-checksums parameter

The new --no-checksums parameter allows for skipping checksums
verifications. This can be used to replace tarballs and still use the
contrib system.

This is useful for atleast the two following cases:

 - Distro developper needs contrib to patch the source, but has the
   original source in the distribution.

 - Distro developper repacks the source, breaking the checksum.

Change-Id: I015ce3d0f6f4fb2f5fd5ec2f95528bfb4b045298
Tuleap: #879

contrib/bootstrap

@@ -24,6 +24,7 @@ usage()
 	echo "  --build=BUILD       configure for building on BUILD"
 	echo "  --host=HOST         cross-compile to build to run on HOST"
 	echo "  --prefix=PREFIX     install files in PREFIX"
+	echo "  --no-checksums      don't verify checksums (allows to replace tarballs)"
 	echo "  --disable-downloads don't download packages from the internet"
 	echo "  --disable-FOO       configure to not build package FOO"
 	echo "  --enable-FOO        configure to build package FOO"
@@ -51,6 +52,9 @@ do
 			usage
 			exit 0
 			;;
+		--no-checksums)
+			DISABLE_CONTRIB_CHECKSUMS="TRUE"
+			;;
 		--disable-downloads)
 			DISABLE_CONTRIB_DOWNLOADS="TRUE"
 			;;
@@ -113,6 +117,7 @@ CROSS_COMPILE ?= $HOST-
 PKGS_DISABLE := $PKGS_DISABLE
 PKGS_ENABLE := $PKGS_ENABLE
 DISABLE_CONTRIB_DOWNLOADS := $DISABLE_CONTRIB_DOWNLOADS
+DISABLE_CONTRIB_CHECKSUMS := $DISABLE_CONTRIB_CHECKSUMS
 EOF
 
 add_make()

contrib/src/main.mak

@@ -337,7 +337,11 @@ checksum = \
 			"$(SRC)/$(patsubst .sum-%,%,$@)/$(2)SUMS" &&) \
 	(cd $(TARBALLS) && $(1) /dev/stdin) < \
 		"$(SRC)/$(patsubst .sum-%,%,$@)/$(2)SUMS"
-CHECK_SHA512 = $(call checksum,$(SHA512SUM),SHA512)
+ifeq ($(DISABLE_CONTRIB_CHECKSUMS),TRUE)
+    CHECK_SHA512 = @echo "Skipping checksum verification..."
+else
+    CHECK_SHA512 = $(call checksum,$(SHA512SUM),SHA512)
+endif
 UNPACK = $(RM) -R $@ \
 	$(foreach f,$(filter %.tar.gz %.tgz,$^), && tar xvzf $(f)) \
 	$(foreach f,$(filter %.tar.bz2,$^), && tar xvjf $(f)) \