[PATCH v2 1/4] subtree: refactor split of a commit into standalone method

[Roger Strain <rstrain@swri.org>]

From: "Strain, Roger L" <roger.strain@swri.org>

In a particularly complex repo, subtree split was not creating
compatible splits for pushing back to a separate repo. Addressing
one of the issues requires recursive handling of parent commits
that were not initially considered by the algorithm. This commit
makes no functional changes, but relocates the code to be called
recursively into a new method to simply comparisons of later
commits.

Signed-off-by: Strain, Roger L <roger.strain@swri.org>
---
 contrib/subtree/git-subtree.sh | 78 ++++++++++++++++++----------------
 1 file changed, 42 insertions(+), 36 deletions(-)

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index d3f39a862..2cd7b345b 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -598,6 +598,47 @@ ensure_valid_ref_format () {
 		die "'$1' does not look like a ref"
 }
 
+process_split_commit () {
+	local rev="$1"
+	local parents="$2"
+	revcount=$(($revcount + 1))
+	progress "$revcount/$revmax ($createcount)"
+	debug "Processing commit: $rev"
+	exists=$(cache_get "$rev")
+	if test -n "$exists"
+	then
+		debug "  prior: $exists"
+		return
+	fi
+	createcount=$(($createcount + 1))
+	debug "  parents: $parents"
+	newparents=$(cache_get $parents)
+	debug "  newparents: $newparents"
+
+	tree=$(subtree_for_commit "$rev" "$dir")
+	debug "  tree is: $tree"
+
+	check_parents $parents
+
+	# ugly.  is there no better way to tell if this is a subtree
+	# vs. a mainline commit?  Does it matter?
+	if test -z "$tree"
+	then
+		set_notree "$rev"
+		if test -n "$newparents"
+		then
+			cache_set "$rev" "$rev"
+		fi
+		return
+	fi
+
+	newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
+	debug "  newrev is: $newrev"
+	cache_set "$rev" "$newrev"
+	cache_set latest_new "$newrev"
+	cache_set latest_old "$rev"
+}
+
 cmd_add () {
 	if test -e "$dir"
 	then
@@ -706,42 +747,7 @@ cmd_split () {
 	eval "$grl" |
 	while read rev parents
 	do
-		revcount=$(($revcount + 1))
-		progress "$revcount/$revmax ($createcount)"
-		debug "Processing commit: $rev"
-		exists=$(cache_get "$rev")
-		if test -n "$exists"
-		then
-			debug "  prior: $exists"
-			continue
-		fi
-		createcount=$(($createcount + 1))
-		debug "  parents: $parents"
-		newparents=$(cache_get $parents)
-		debug "  newparents: $newparents"
-
-		tree=$(subtree_for_commit "$rev" "$dir")
-		debug "  tree is: $tree"
-
-		check_parents $parents
-
-		# ugly.  is there no better way to tell if this is a subtree
-		# vs. a mainline commit?  Does it matter?
-		if test -z "$tree"
-		then
-			set_notree "$rev"
-			if test -n "$newparents"
-			then
-				cache_set "$rev" "$rev"
-			fi
-			continue
-		fi
-
-		newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
-		debug "  newrev is: $newrev"
-		cache_set "$rev" "$newrev"
-		cache_set latest_new "$newrev"
-		cache_set latest_old "$rev"
+		process_split_commit "$rev" "$parents"
 	done || exit $?
 
 	latest_new=$(cache_get latest_new)
-- 
2.19.1