Makefile: introduce SANE_TOOL_PATH for prepending required elements to PATH

Some platforms (like SunOS and family) have kept their common binaries at
some historical moment in time, and introduced new binaries with modern
features in a special location like /usr/xpg4/bin or /usr/ucb.  Some of the
features provided by these modern binaries are expected and required by git.
If the featureful binaries are not in the users path, then git could end up
using the less featureful binary and fail.

So provide a mechanism to prepend elements to the users PATH at runtime so
the modern binaries will be found.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -3,6 +3,11 @@ all::
 
 # Define V=1 to have a more verbose compile.
 #
+# Define SHELL_PATH to a POSIX shell if your /bin/sh is broken.
+#
+# Define SANE_TOOL_PATH to a colon-separated list of paths to prepend
+# to PATH if your tools in /usr/bin are broken.
+#
 # Define SNPRINTF_RETURNS_BOGUS if your are on a system which snprintf()
 # or vsnprintf() return -1 instead of number of characters which would
 # have been written to the final string if enough space had been available.
@@ -702,6 +707,7 @@ ifeq ($(uname_S),SunOS)
 	NEEDS_SOCKET = YesPlease
 	NEEDS_NSL = YesPlease
 	SHELL_PATH = /bin/bash
+	SANE_TOOL_PATH = /usr/xpg6/bin:/usr/xpg4/bin
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
 	NO_MKDTEMP = YesPlease
@@ -864,6 +870,13 @@ endif
 -include config.mak.autogen
 -include config.mak
 
+ifdef SANE_TOOL_PATH
+BROKEN_PATH_FIX = s|^. @@PATH@@|PATH=$(SANE_TOOL_PATH)|
+PATH := $(SANE_TOOL_PATH):${PATH}
+else
+BROKEN_PATH_FIX = d
+endif
+
 ifeq ($(uname_S),Darwin)
 	ifndef NO_FINK
 		ifeq ($(shell test -d /sw/lib && echo y),y)
@@ -1265,6 +1278,7 @@ $(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
 	    -e 's|@SHELL_PATH@|$(SHELL_PATH_SQ)|' \
 	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
 	    -e 's/@@NO_CURL@@/$(NO_CURL)/g' \
+	    -e '/^# @@PATH@@/$(BROKEN_PATH_FIX)' \
 	    $@.sh >$@+ && \
 	chmod +x $@+ && \
 	mv $@+ $@

git-sh-setup.sh

@@ -11,6 +11,8 @@
 # exporting it.
 unset CDPATH
 
+# @@PATH@@:$PATH
+
 die() {
 	echo >&2 "$@"
 	exit 1