unaccent: Tweak value of PYTHON when building without Python support

As coded, the module's Makefile would fail to set a value for PYTHON as
it checked if the variable is defined.  When compiling without
--with-python, PYTHON is defined and set to an empty value, so the
existing check is not able to do its work.

This commit switches the rule to check if the value is empty rather than
defined, allowing the generation of unaccent.rules even if --with-python
is not used as long as "python" exists.  BISON and FLEX do the same in
pgxs.mk, for instance.

Thinko in f85a485f89e2.

Author: Japin Li
Discussion: https://postgr.es/m/MEYP282MB1669F86C0DC7B4DC48489CB0B6C3A@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
Backpatch-through: 13

diff --git a/contrib/unaccent/Makefile b/contrib/unaccent/Makefile
index b8307d1601e8e3eab1c3eb8330c7661b8e94b2dc..9e42f3e638a56b629bfb1635ca664fe463c9f997 100644 (file)
--- a/contrib/unaccent/Makefile
+++ b/contrib/unaccent/Makefile
@@ -30,7 +30,9 @@ endif
 update-unicode: unaccent.rules
 
 # Allow running this even without --with-python
-PYTHON ?= python
+ifeq ($(PYTHON),)
+PYTHON = python
+endif
 
 unaccent.rules: generate_unaccent_rules.py ../../src/common/unicode/UnicodeData.txt Latin-ASCII.xml
    $(PYTHON) $< --unicode-data-file $(word 2,$^) --latin-ascii-file $(word 3,$^) >$@