From 94d7c884c38561dba467feef3acf6ada50713e59 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Wed, 13 Dec 2017 21:46:03 -0500 Subject: testing: do not crash when m.Run is called twice and -test.testlogfile is used MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Tests exist that call m.Run in a loop‽ Now we have one too. Fixes #23129. Change-Id: I8cbecb724f239ae14ad45d75e67d12c80e41c994 Reviewed-on: https://go-review.googlesource.com/83956 Run-TryBot: Russ Cox TryBot-Result: Gobot Gobot Reviewed-by: Ian Lance Taylor --- src/testing/testing.go | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'src/testing/testing.go') diff --git a/src/testing/testing.go b/src/testing/testing.go index 13937b6ad4..3a4e256b49 100644 --- a/src/testing/testing.go +++ b/src/testing/testing.go @@ -914,6 +914,8 @@ type M struct { timer *time.Timer afterOnce sync.Once + + numRun int } // testDeps is an internal interface of functionality that is @@ -945,6 +947,12 @@ func MainStart(deps testDeps, tests []InternalTest, benchmarks []InternalBenchma // Run runs the tests. It returns an exit code to pass to os.Exit. func (m *M) Run() int { + // Count the number of calls to m.Run. + // We only ever expected 1, but we didn't enforce that, + // and now there are tests in the wild that call m.Run multiple times. + // Sigh. golang.org/issue/23129. + m.numRun++ + // TestMain may have already called flag.Parse. if !flag.Parsed() { flag.Parse() @@ -1110,7 +1118,16 @@ func (m *M) before() { if *testlog != "" { // Note: Not using toOutputDir. // This file is for use by cmd/go, not users. - f, err := os.Create(*testlog) + var f *os.File + var err error + if m.numRun == 1 { + f, err = os.Create(*testlog) + } else { + f, err = os.OpenFile(*testlog, os.O_WRONLY, 0) + if err == nil { + f.Seek(0, io.SeekEnd) + } + } if err != nil { fmt.Fprintf(os.Stderr, "testing: %s\n", err) os.Exit(2) -- cgit v1.3-5-g45d5