Makefile: Normalize $(bindir) and $(gitexecdir) before comparing

The install target needs to check whether the user has opted to make
$(gitexecdir) equal to $(bindir). It did so by a straight string
comparison. Since we are going to allow a relative $(gitexecdir), we have
to normalize paths before comparison, which we do with $(cd there && pwd).

The normalized paths are stored in shell variables. These we can now
reuse in the subsequent install statements, which conveniently shortens
the lines a bit.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1332,19 +1332,19 @@ ifndef NO_TCLTK
 	$(MAKE) -C gitk-git install
 	$(MAKE) -C git-gui install
 endif
-	if test 'z$(bindir_SQ)' != 'z$(gitexecdir_SQ)'; \
-	then \
-		ln -f '$(DESTDIR_SQ)$(bindir_SQ)/git$X' \
-			'$(DESTDIR_SQ)$(gitexecdir_SQ)/git$X' || \
-		cp '$(DESTDIR_SQ)$(bindir_SQ)/git$X' \
-			'$(DESTDIR_SQ)$(gitexecdir_SQ)/git$X'; \
-	fi
-	$(foreach p,$(BUILT_INS), $(RM) '$(DESTDIR_SQ)$(gitexecdir_SQ)/$p' && ln '$(DESTDIR_SQ)$(gitexecdir_SQ)/git$X' '$(DESTDIR_SQ)$(gitexecdir_SQ)/$p' ;)
-	$(RM) '$(DESTDIR_SQ)$(gitexecdir_SQ)/git$X'
 ifneq (,$X)
 	$(foreach p,$(patsubst %$X,%,$(filter %$X,$(ALL_PROGRAMS) $(BUILT_INS) git$X)), $(RM) '$(DESTDIR_SQ)$(gitexecdir_SQ)/$p';)
 endif
-	./check_bindir 'z$(bindir_SQ)' 'z$(gitexecdir_SQ)' '$(DESTDIR_SQ)$(bindir_SQ)/git-shell$X'
+	bindir=$$(cd '$(DESTDIR_SQ)$(bindir_SQ)' && pwd) && \
+	execdir=$$(cd '$(DESTDIR_SQ)$(gitexecdir_SQ)' && pwd) && \
+	if test "z$$bindir" != "z$$execdir"; \
+	then \
+		ln -f "$$bindir/git$X" "$$execdir/git$X" || \
+		cp "$$bindir/git$X" "$$execdir/git$X"; \
+	fi && \
+	{ $(foreach p,$(BUILT_INS), $(RM) "$$execdir/$p" && ln "$$execdir/git$X" "$$execdir/$p" ;) } && \
+	$(RM) "$$execdir/git$X" && \
+	./check_bindir "z$$bindir" "z$$execdir" "$$bindir/git-shell$X"
 
 install-doc:
 	$(MAKE) -C Documentation install