Add `--patch` flag to apply a Ruby patch from stdin

If `-p|--patch` flag was set while invoking `ruby-build` or
`rbenv install`, ruby-build will use `patch -p0 -i -` to apply a patch
from stdin to Ruby, Rubinius, or JRuby source code before running the
rest of `build_package_*` commands.

References #443

bin/rbenv-install

@@ -2,8 +2,8 @@
 #
 # Summary: Install a Ruby version using the ruby-build plugin
 #
-# Usage: rbenv install [-f|--force] [-k|--keep] [-v|--verbose] <version>
-#        rbenv install [-f|--force] [-k|--keep] [-v|--verbose] <definition-file>
+# Usage: rbenv install [-f|--force] [-k|--keep] [-v|--verbose] [-p|--patch] <version>
+#        rbenv install [-f|--force] [-k|--keep] [-v|--verbose] [-p|--patch] <definition-file>
 #        rbenv install -l|--list
 #
 #   -l/--list        List all available versions
@@ -11,6 +11,7 @@
 #   -k/--keep        Keep source tree in $RBENV_BUILD_ROOT after installation
 #                    (defaults to $RBENV_ROOT/sources)
 #   -v/--verbose     Verbose mode: print compilation status to stdout
+#   -p/--patch       Apply a patch from stdin before building
 #
 # For detailed information on installing Ruby versions with
 # ruby-build, including a list of environment variables for adjusting
@@ -49,6 +50,7 @@ indent() {
 unset FORCE
 unset KEEP
 unset VERBOSE
+unset HAS_PATCH
 
 parse_options "$@"
 for option in "${OPTIONS[@]}"; do
@@ -70,6 +72,9 @@ for option in "${OPTIONS[@]}"; do
   "v" | "verbose" )
     VERBOSE="-v"
     ;;
+  "p" | "patch" )
+    HAS_PATCH="-p"
+    ;;
   "version" )
     exec ruby-build --version
     ;;
@@ -161,7 +166,7 @@ trap cleanup SIGINT
 
 # Invoke `ruby-build` and record the exit status in $STATUS.
 STATUS=0
-ruby-build $KEEP $VERBOSE "$DEFINITION" "$PREFIX" || STATUS="$?"
+ruby-build $KEEP $VERBOSE $HAS_PATCH "$DEFINITION" "$PREFIX" || STATUS="$?"
 
 # Display a more helpful message if the definition wasn't found.
 if [ "$STATUS" == "2" ]; then

bin/ruby-build

@@ -364,6 +364,8 @@ build_package() {
 
   echo "Installing ${package_name}..." >&2
 
+  [ -n "$HAS_PATCH" ] && apply_ruby_patch "$package_name"
+
   for command in $commands; do
     "build_package_${command}" "$package_name"
   done
@@ -770,13 +772,21 @@ isolated_gem_install() {
   gem install "$@"
 }
 
+apply_ruby_patch() {
+  case "$1" in
+  ruby-* | jruby-* | rubinius-* )
+    patch -p0 -i "${2:--}"
+    ;;
+  esac
+}
+
 version() {
   echo "ruby-build ${RUBY_BUILD_VERSION}"
 }
 
 usage() {
   { version
-    echo "usage: ruby-build [-k|--keep] [-v|--verbose] definition prefix"
+    echo "usage: ruby-build [-k|--keep] [-v|--verbose] [-p|--patch] definition prefix"
     echo "       ruby-build --definitions"
   } >&2
 
@@ -796,6 +806,7 @@ list_definitions() {
 
 unset VERBOSE
 unset KEEP_BUILD_PATH
+unset HAS_PATCH
 RUBY_BUILD_ROOT="$(abs_dirname "$0")/.."
 
 parse_options "$@"
@@ -807,6 +818,7 @@ for option in "${OPTIONS[@]}"; do
     { echo
       echo "  -k/--keep        Do not remove source tree after installation"
       echo "  -v/--verbose     Verbose mode: print compilation status to stdout"
+      echo "  -p/--patch       Apply a patch from stdin before building"
       echo "  --definitions    List all built-in definitions"
       echo
     } >&2
@@ -822,6 +834,9 @@ for option in "${OPTIONS[@]}"; do
   "v" | "verbose" )
     VERBOSE=true
     ;;
+  "p" | "patch" )
+    HAS_PATCH=true
+    ;;
   "version" )
     version
     exit 0

test/build.bats

@@ -71,6 +71,30 @@ make -j 2
 OUT
 }
 
+@test "apply ruby patch before building" {
+  cached_tarball "yaml-0.1.4"
+  cached_tarball "ruby-2.0.0"
+
+  stub brew false
+  stub_make_install
+  stub_make_install
+  stub patch ' : echo patch "$@" >> build.log'
+
+  install_fixture --patch definitions/needs-yaml
+  assert_success
+
+  unstub make
+  unstub patch
+
+  assert_build_log <<OUT
+yaml-0.1.4: --prefix=$INSTALL_ROOT
+make -j 2
+patch -p0 -i -
+ruby-2.0.0: --prefix=$INSTALL_ROOT
+make -j 2
+OUT
+}
+
 @test "yaml is linked from Homebrew" {
   cached_tarball "ruby-2.0.0"
 

test/test_helper.bash

@@ -51,11 +51,18 @@ run_inline_definition() {
 }
 
 install_fixture() {
+  local args
+
+  while [ "${1#-}" != "$1" ]; do
+    args="$args $1"
+    shift 1
+  done
+
   local name="$1"
   local destination="$2"
   [ -n "$destination" ] || destination="$INSTALL_ROOT"
 
-  run ruby-build "$FIXTURE_ROOT/$name" "$destination"
+  run ruby-build $args "$FIXTURE_ROOT/$name" "$destination"
 }
 
 assert() {