1 file changed, 17 insertions, 17 deletions

diff --git a/source/gen-version.sh b/source/gen-version.sh
index fb7d459..b28e987 100755
--- a/source/gen-version.sh
+++ b/source/gen-version.sh
@@ -1,27 +1,27 @@
 #!/bin/sh
+# Writes a "CGIT_VERSION = ..." line into the output file, which the build
+# then includes. Run it from the project root, as gen-version.sh <fallback>
+# [output], so that git describe reports cgit rather than the bundled git
+# submodule. The output file defaults to VERSION.
 
-# Writes a "CGIT_VERSION = ..." line to the output file (default: VERSION),
-# for the build to include. Run from the project root so `git describe` acts
-# on cgit rather than the bundled Git submodule.
-#
-# Usage: gen-version.sh <fallback-version> [output-file]
+version=$1
+output=${2:-VERSION}
 
-V=$1
-OUT=${2:-VERSION}
-
-# Prefer `git describe` when run at the top of the cgit working tree,
-# keeping the fallback when it fails, as in a shallow tagless clone.
+# Prefer what git describe reports, but only at the top of the cgit working
+# tree, and keep the fallback when it has nothing to say, as in a shallow or
+# tagless clone.
 if test "$(git rev-parse --git-dir 2>/dev/null)" = '.git'
 then
-	D=$(git describe --abbrev=4 HEAD 2>/dev/null)
-	test -n "$D" && V=$D
+	described=$(git describe --abbrev=4 HEAD 2>/dev/null)
+	test -n "$described" && version=$described
 fi
 
-new="CGIT_VERSION = $V"
-old=$(cat "$OUT" 2>/dev/null)
+new="CGIT_VERSION = $version"
+old=$(cat "$output" 2>/dev/null)
 
-# Exit if the version is already up to date.
+# Leaving the file untouched when nothing changed keeps make from rebuilding
+# everything that depends on it.
 test "$old" = "$new" && exit 0
 
-echo "$new" > "$OUT"
-cat "$OUT"
+echo "$new" > "$output"
+cat "$output"