1 files changed, 31 insertions, 18 deletions
diff --git a/Library/Homebrew/utils/curl.rb b/Library/Homebrew/utils/curl.rb
index 5a40ae846..52d03c93e 100644
--- a/Library/Homebrew/utils/curl.rb
+++ b/Library/Homebrew/utils/curl.rb
@@ -1,42 +1,55 @@
 require "pathname"
 require "open3"
 
-def curl_args(options = {})
+def curl_executable
   curl = Pathname.new ENV["HOMEBREW_CURL"]
   curl = Pathname.new "/usr/bin/curl" unless curl.exist?
-  raise "#{curl} is not executable" unless curl.exist? && curl.executable?
+  return curl if curl.executable?
+  raise "#{curl} is not executable"
+end
 
+def curl_args(*extra_args, show_output: false, user_agent: :default)
   args = [
-    curl.to_s,
-    "--remote-time",
-    "--location",
+    curl_executable.to_s,
+    "--show-error",
   ]
 
-  case options[:user_agent]
-  when :browser
-    args << "--user-agent" << HOMEBREW_USER_AGENT_FAKE_SAFARI
+  args << "--user-agent" << case user_agent
+  when :browser, :fake
+    HOMEBREW_USER_AGENT_FAKE_SAFARI
+  when :default
+    HOMEBREW_USER_AGENT_CURL
   else
-    args << "--user-agent" << HOMEBREW_USER_AGENT_CURL
+    user_agent
   end
 
-  unless options[:show_output]
+  unless show_output
+    args << "--fail"
     args << "--progress-bar" unless ARGV.verbose?
     args << "--verbose" if ENV["HOMEBREW_CURL_VERBOSE"]
-    args << "--fail"
     args << "--silent" if !$stdout.tty? || ENV["TRAVIS"]
   end
 
-  args += options[:extra_args] if options[:extra_args]
-  args
+  args + extra_args
 end
 
 def curl(*args)
-  safe_system(*curl_args(extra_args: args))
+  safe_system(*curl_args(*args))
 end
 
-def curl_output(*args)
-  curl_args = curl_args(extra_args: args, show_output: true)
-  Open3.popen3(*curl_args) do |_, stdout, stderr, wait_thread|
-    [stdout.read, stderr.read, wait_thread.value]
+def curl_download(*args, to: nil, **options)
+  continue_at ||= "-"
+  curl("--location", "--remote-time", "--continue-at", continue_at, "--output", to, *args, **options)
+rescue ErrorDuringExecution
+  # `curl` error 33: HTTP server doesn't seem to support byte ranges. Cannot resume.
+  if $CHILD_STATUS.exitstatus == 33 && continue_at == "-"
+    continue_at = "0"
+    retry
   end
+
+  raise
+end
+
+def curl_output(*args, **options)
+  Open3.capture3(*curl_args(*args, show_output: true, **options))
 end