Auto merge of #3874 - bundler:seg-settings-permission-error, r=indirect

Raise permission error when config file isn't readable

Closes #3858

2 files changed, 12 insertions, 4 deletions

diff --git a/lib/bundler.rb b/lib/bundler.rb
index 109cf287e6..5bb35f4d40 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -86,14 +86,21 @@ module Bundler
   class MarshalError < StandardError; end
 
   class PermissionError < BundlerError
-    def initialize(file)
+    def initialize(file, permission_type = :write)
       @file = file
+      @permission_type = permission_type
     end
 
     def message
-      "There was an error while trying to write to `#{File.basename(@file)}`. It is likely that \n" \
-      "you need to allow write permissions for the file at path: \n" \
-      "#{File.expand_path(@file)}"
+      action = case @permission_type
+               when :read then "read from"
+               when :write then "write to"
+               when :executable then "execute"
+               else @permission_type.to_s
+               end
+      "There was an error while trying to #{action} `#{File.basename(@file)}`. " \
+      "It is likely that you need to grant #{@permission_type} permissions for " \
+      "the file at path: `#{File.expand_path(@file)}`."
     end
 
     status_code(23)
diff --git a/lib/bundler/settings.rb b/lib/bundler/settings.rb
index 14d3f4d683..898817c963 100644
--- a/lib/bundler/settings.rb
+++ b/lib/bundler/settings.rb
@@ -229,6 +229,7 @@ module Bundler
       valid_file = config_file && config_file.exist? && !config_file.size.zero?
       if !ignore_config? && valid_file
         config_regex = /^(BUNDLE_.+): (['"]?)(.*(?:\n(?!BUNDLE).+)?)\2$/
+        raise PermissionError.new(config_file, :read) unless config_file.readable?
         config_pairs = config_file.read.scan(config_regex).map do |m|
           key, _, value = m
           [convert_to_backward_compatible_key(key), value.gsub(/\s+/, " ").tr('"', "'")]