+if $GZIP --version >/dev/null 2>&1; then
+ test_set_prereq GZIP
+else
+ say "Skipping some tar.gz tests because gzip not found"
+fi
+
+test_expect_success GZIP 'git archive --format=tgz' '
+ git archive --format=tgz HEAD >j.tgz
+'
+
+test_expect_success GZIP 'git archive --format=tar.gz' '
+ git archive --format=tar.gz HEAD >j1.tar.gz &&
+ test_cmp j.tgz j1.tar.gz
+'
+
+test_expect_success GZIP 'infer tgz from .tgz filename' '
+ git archive --output=j2.tgz HEAD &&
+ test_cmp j.tgz j2.tgz
+'
+
+test_expect_success GZIP 'infer tgz from .tar.gz filename' '
+ git archive --output=j3.tar.gz HEAD &&
+ test_cmp j.tgz j3.tar.gz
+'
+
+if $GUNZIP --version >/dev/null 2>&1; then
+ test_set_prereq GUNZIP
+else
+ say "Skipping some tar.gz tests because gunzip was not found"
+fi
+
+test_expect_success GZIP,GUNZIP 'extract tgz file' '
+ $GUNZIP -c <j.tgz >j.tar &&
+ test_cmp b.tar j.tar
+'
+