Rename the extracted directory if it is not the same as the package name

* make_package() assumes the archive was extracted to $package_name.
* fetch_tarball() does not check the name of the toplevel directory in
  the archive, so rename after if it's not exactly "$package_name".

Author: eregon

bin/ruby-build

@@ -350,6 +350,7 @@ fetch_tarball() {
   local package_url="$2"
   local mirror_url
   local checksum
+  local extracted_dir
 
   if [ "$package_url" != "${package_url/\#}" ]; then
     checksum="${package_url#*#}"
@@ -382,6 +383,11 @@ fetch_tarball() {
   fi
 
   { if tar $tar_args "$package_filename"; then
+      if [ ! -d "$package_name" ]; then
+        extracted_dir=$(find_extracted_directory)
+        mv "$extracted_dir" "$package_name"
+      fi
+
       if [ -z "$KEEP_BUILD_PATH" ]; then
         rm -f "$package_filename"
       else
@@ -391,6 +397,17 @@ fetch_tarball() {
   } >&4 2>&1
 }
 
+find_extracted_directory() {
+  for f in *; do
+    if [ -d "$f" ]; then
+      echo "$f"
+      return
+    fi
+  done
+  echo "Extracted directory not found" >&2
+  return 1
+}
+
 reuse_existing_tarball() {
   local package_filename="$1"
   local checksum="$2"