Fix Schrodinger's file existence check in file matcher

See: https://stackoverflow.com/a/12518877/1048862 For example, trying to check the existence of "/www/index.php/index.php" fails but not with an os.IsNotExist()-type error. So we have to assume that a file that cannot be successfully stat'ed at all does not exist.

Matthew Holt committed Sep 6, 2019 at 12:57 UTC 4bd949652564eff8ccfc50f105f0d35f0af26402

1 file changed +14 -2

modules/caddyhttp/fileserver/matcher.go

+14 -2

@@ -207,10 +207,22 @@ func (m MatchFile) selectFile(r *http.Request) (rel, abs string, matched bool) {

207 return

208 }

209

210 -// fileExists returns true if file exists.

210 +// fileExists returns true if file exists,

211 +// false if it doesn't, or false if there

212 +// was any other error.

213 func fileExists(file string) bool {

214 _, err := os.Stat(file)

213 - return !os.IsNotExist(err)

215 + if err == nil {

216 + return true

217 + } else if os.IsNotExist(err) {

218 + return false

219 + } else {

220 + // we don't know if it exists,

221 + // so assume it doesn't, since

222 + // there must have been some

223 + // other error anyway

224 + return false

225 + }

226 }

227

228 const (