fix: ensure we can disable setting the rev-env-var

plugins/common/property-functions

@@ -27,6 +27,20 @@ fn-plugin-property-destroy() {
   fi
 }
 
+fn-plugin-property-exists() {
+  declare desc="returns whether the property store has a value for an app"
+  declare PLUGIN="$1" APP="$2" KEY="$3" DEFAULT="$4"
+  local CONFIG_VALUE
+
+  if [[ -z "$PLUGIN" ]] || [[ -z "$APP" ]] || [[ -z "$KEY" ]]; then
+    return 1
+  fi
+
+  if [[ ! -f "${DOKKU_LIB_ROOT:?}/config/${PLUGIN}/${APP}/${KEY}" ]]; then
+    return 1
+  fi
+}
+
 fn-plugin-property-get() {
   declare desc="returns the property store value for an app"
   declare PLUGIN="$1" APP="$2" KEY="$3" DEFAULT="$4"

plugins/git/functions

@@ -152,14 +152,18 @@ git_hook_cmd() {
 
 git_build() {
   declare desc="setup and call git_build_app_repo"
-  local APP="$1"
+  local APP="$1" REV="$2"
   local DOKKU_DEPLOY_BRANCH ENV_VAR_NAME REF
   if [[ $# -ge 2 ]]; then
-    ENV_VAR_NAME="$(fn-plugin-property-get "git" "$APP" "rev-env-var" "GIT_REV")"
+    ENV_VAR_NAME="$(fn-plugin-property-get "git" "$APP" "rev-env-var")"
+    if [[ -z "$ENV_VAR_NAME" ]] && ! fn-plugin-property-exists  "git" "$APP" "rev-env-var"; then
+      ENV_VAR_NAME="GIT_REV"
+    fi
+
     if [[ -n "$ENV_VAR_NAME" ]]; then
       config_set --no-restart "$APP" "${ENV_VAR_NAME}=${REV}" > /dev/null
     fi
-    local REF="$2"
+    local REF="$REV"
   else
     DOKKU_DEPLOY_BRANCH="$(git_deploy_branch "$APP")"
     REF=$(< "$DOKKU_ROOT/$APP/refs/heads/$DOKKU_DEPLOY_BRANCH")

plugins/git/subcommands/set

@@ -30,9 +30,13 @@ git-set-cmd() {
     fn-plugin-property-write "git" "$APP" "$KEY" "$VALUE"
   else
     dokku_log_info2_quiet "Unsetting ${KEY}"
-    fn-plugin-property-delete "git" "$APP" "$KEY"
-    if [[ "$KEY" == "enabled" ]]; then
-      fn-plugin-property-destroy "git" "$APP"
+    if [[ "$KEY" == "rev-env-var" ]]; then
+      fn-plugin-property-write "git" "$APP" "$KEY" "$VALUE"
+    else
+      fn-plugin-property-delete "git" "$APP" "$KEY"
+      if [[ "$KEY" == "enabled" ]]; then
+        fn-plugin-property-destroy "git" "$APP"
+      fi
     fi
   fi
 }

tests/unit/10_git.bats

@@ -68,7 +68,7 @@ teardown() {
   run bash -c "dokku config:get $TEST_APP GIT_REV"
   echo "output: "$output
   echo "status: "$status
-  assert_output_empty
+  assert_output ""
 }
 
 @test "(git) customize the GIT_REV environment variable" {

tests/unit/test_helper.bash

@@ -77,12 +77,6 @@ assert_output_exists() {
   [[ -n "$output" ]] || flunk "expected output, found none"
 }
 
-# ShellCheck doesn't know about $output from Bats
-# shellcheck disable=SC2154
-assert_output_empty() {
-  [[ -z "$output" ]] || flunk "expected no output, found $output"
-}
-
 # ShellCheck doesn't know about $output from Bats
 # shellcheck disable=SC2154
 assert_output_contains() {