make GANA update more compatible with incremental compilation (fixes #6431)

bootstrap

@@ -7,15 +7,7 @@ if ! git --version >/dev/null; then
   exit 1
 fi
 
-git submodule update --init
-
-# Generate taler-error-codes.h in gana and copy it to
-# src/include/taler_error_codes.h
-cd contrib/gana/gnu-taler-error-codes
-make
-cd ../../..
-cp contrib/gana/gnu-taler-error-codes/taler_error_codes.h src/include/taler_error_codes.h
-cp contrib/gana/gnu-taler-error-codes/taler_error_codes.c src/util/taler_error_codes.c
+./contrib/gana.sh
 
 # This is more portable than `which' but comes with
 # the caveat of not(?) properly working on busybox's ash:

contrib/gana

@@ -1 +1 @@
-Subproject commit 22192612aab2bf0a5e1e5d452b31fb47594698ee
+Subproject commit 0a9293b4cf1df97c395dc96d7a8ba96cc1fb4664

contrib/gana.sh

@@ -1,13 +1,24 @@
 #!/bin/sh
 # Helper script to update to latest GANA
-# Run from exchange/ main directory; make sure you have
-# no uncommitted changes at the time of running the script.
+# Run from exchange/ main directory.
 set -eu
+
+git submodule update --init
+
 cd contrib/gana
 git pull origin master
 cd ../..
-git commit -a -S -m "synchronize with latest GANA"
-./bootstrap
-cd src/include
-make install
-cd ../..
+
+# Generate taler-error-codes.h in gana and copy it to
+# src/include/taler_error_codes.h
+cd contrib/gana/gnu-taler-error-codes
+make
+cd ../../..
+if ! diff contrib/gana/gnu-taler-error-codes/taler_error_codes.h src/include/taler_error_codes.h > /dev/null
+then
+  echo "Deploying latest new GANA database..."
+  cp contrib/gana/gnu-taler-error-codes/taler_error_codes.h src/include/taler_error_codes.h
+  cp contrib/gana/gnu-taler-error-codes/taler_error_codes.c src/util/taler_error_codes.c
+else
+  echo "GANA database already up-to-date"
+fi