Fix GO_BUILD_MIRROR_URL not working (#446)

Author: hongweipeng

plugins/go-build/bin/go-build

@@ -453,7 +453,9 @@ http() {
   local file="$3"
   [ -n "$url" ] || return 1
 
-  if [[ -z $GO_BUILD_MIRROR_URL ]] && [[ $IS_TEST != "true" ]]; then
+  if [ -n "$GO_BUILD_MIRROR_URL" ] && [ -z "$IS_TEST" ]; then
+    url="$GO_BUILD_MIRROR_URL/${url}"
+  else
     url="https://go.dev/dl/${url}"
   fi
 
@@ -502,18 +504,11 @@ http_get_wget() {
 fetch_tarball() {
   local package_name="$1"
   local package_url="$2"
-  local mirror_url
   local checksum
 
   if [ "$package_url" != "${package_url/\#/}" ]; then
     checksum="${package_url#*#}"
     package_url="${package_url%%#*}"
-
-    if [ -n "$GO_BUILD_MIRROR_URL" ]; then
-      if [[ -z "$GO_BUILD_DEFAULT_MIRROR" || $package_url != */go.dev/* ]]; then
-        mirror_url="${GO_BUILD_MIRROR_URL}/$checksum"
-      fi
-    fi
   fi
 
   local tar_args="xzf"
@@ -538,9 +533,7 @@ fetch_tarball() {
   if ! reuse_existing_tarball "$package_filename" "$checksum"; then
     local tarball_filename=$(basename $package_url)
     echo "Downloading ${tarball_filename}..." >&2
-    http head "$mirror_url" &&
-      download_tarball "$mirror_url" "$package_filename" "$checksum" ||
-      download_tarball "$package_url" "$package_filename" "$checksum"
+    download_tarball "$package_url" "$package_filename" "$checksum"
   fi
 
   {
@@ -638,25 +631,18 @@ fetch_git() {
 fetch_zip() {
   local package_name="$1"
   local package_url="$2"
-  local mirror_url
   local checksum
 
   if [ "$package_url" != "${package_url/\#/}" ]; then
     checksum="${package_url#*#}"
     package_url="${package_url%%#*}"
-
-    if [ -n "$GO_BUILD_MIRROR_URL" ]; then
-      mirror_url="${GO_BUILD_MIRROR_URL}/$checksum"
-    fi
   fi
 
   local package_filename="${package_name}.zip"
 
   if ! reuse_existing_tarball "$package_filename" "$checksum"; then
     echo "Downloading ${package_filename}..." >&2
-    http head "$mirror_url" &&
-      download_tarball "$mirror_url" "$package_filename" "$checksum" ||
-      download_tarball "$package_url" "$package_filename" "$checksum"
+    download_tarball "$package_url" "$package_filename" "$checksum"
   fi
 
   {