Linux standalone: Use md5sum to shorten paths in .cache/git-annex/locales

md5sum is part of busybox, so is probably available unless it were compiled
out. If md5sum (or cut for that matter) is not available, it will
still use the whole path to $base, otherwise hash it.

Of course it's possible for md5sum to be available sometimes and not others
on the same system; in such an event the locales would be built twice for
the same bundle. The cleanup code will delete both sets once that
version of the bundle is upgraded.

CHANGELOG

@@ -12,6 +12,7 @@ git-annex (8.20200227) UNRELEASED; urgency=medium
   * stack.yaml: Updated to lts-14.27.
   * git-annex config: Only allow configs be set that are ones git-annex actually
     supports reading from repo-global config, to avoid confusion.
+  * Linux standalone: Use md5sum to shorten paths in .cache/git-annex/locales
 
  -- Joey Hess <id@joeyh.name>  Thu, 27 Feb 2020 00:44:11 -0400
 

doc/bugs/git-annex_standalone_runshell_locale_cache_fails_on_too-long_filenames.mdwn

@@ -3,3 +3,5 @@ In the standalone build of git-annex, the runshell script caches locale info in
 When the full path is too long, this fails with the error "filename too long".
 
 Also, if the locale info is specific to the standalone environment, maybe it could be built as part of the process that creates the standalone package, rather than built on-the-fly and cached in the user's home dir?
+
+> [[fixed|done]] --[[Joey]]

standalone/linux/skel/runshell

@@ -129,6 +129,11 @@ ORIG_LOCPATH="$LOCPATH"
 export ORIG_LOCPATH
 if [ -z "${LOCPATH+set}" ] && [ -z "$GIT_ANNEX_PACKAGE_INSTALL" ]; then
 	LOCPATH="$HOME/.cache/git-annex/locales/$(echo "$base" | tr / _ )"
+	# try to generate a short version, if md5sum is available
+	locpathmd5=$( (echo "$LOCPATH" | md5sum | cut -d ' ' -f 1 2>/dev/null) || true)
+	if [ -n "$locpathmd5" ]; then
+		LOCPATH="$HOME/.cache/git-annex/locales/$locpathmd5"
+	fi
 	export LOCPATH
 	
 	# Clean up locale caches when their standalone bundle no longer exists.