[release-branch.go1.12] path/filepath: revert "fix Windows-specific Clean bug"

ianlancetaylor · ianlancetaylor · commit c55fb33612cd · 2019-02-26T23:44:04.000Z
Revert CL 137055, which changed Clean("\\somepath\dir\") to return "\\somepath\dir" on Windows. It's not entirely clear this is correct, as this path is really "\\server\share\", and as such the trailing slash may be the path on that share, much like "C:\". In any case, the change broke existing code, so roll it back for now and rethink for 1.13. Updates #27791 Updates #30307 Change-Id: I69200b1efe38bdb6d452b744582a2bfbb3acbcec Reviewed-on: https://go-review.googlesource.com/c/163077 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com> (cherry picked from commit 153c0da) Reviewed-on: https://go-review.googlesource.com/c/163078 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/path/filepath/path.go b/src/path/filepath/path.go
@@ -96,19 +96,14 @@ func Clean(path string) string {
 		}
 		return originalPath + "."
 	}
-
-	n := len(path)
-	if volLen > 2 && n == 1 && os.IsPathSeparator(path[0]) {
-		// UNC volume name with trailing slash.
-		return FromSlash(originalPath[:volLen])
-	}
 	rooted := os.IsPathSeparator(path[0])
 
 	// Invariants:
 	//	reading from path; r is index of next byte to process.
-	//	writing to out; w is index of next byte to write.
-	//	dotdot is index in out where .. must stop, either because
+	//	writing to buf; w is index of next byte to write.
+	//	dotdot is index in buf where .. must stop, either because
 	//		it is the leading slash or it is a leading ../../.. prefix.
+	n := len(path)
 	out := lazybuf{path: path, volAndPath: originalPath, volLen: volLen}
 	r, dotdot := 0, 0
 	if rooted {
diff --git a/src/path/filepath/path_test.go b/src/path/filepath/path_test.go
@@ -93,9 +93,6 @@ var wincleantests = []PathTest{
 	{`//host/share/foo/../baz`, `\\host\share\baz`},
 	{`\\a\b\..\c`, `\\a\b\c`},
 	{`\\a\b`, `\\a\b`},
-	{`\\a\b\`, `\\a\b`},
-	{`\\folder\share\foo`, `\\folder\share\foo`},
-	{`\\folder\share\foo\`, `\\folder\share\foo`},
 }
 
 func TestClean(t *testing.T) {

Original file line number	Diff line number	Diff line change
`@@ -93,9 +93,6 @@ var wincleantests = []PathTest{`
`93`	`93`	{`//host/share/foo/../baz`, `\\host\share\baz`},
`94`	`94`	{`\\a\b\..\c`, `\\a\b\c`},
`95`	`95`	{`\\a\b`, `\\a\b`},
`96`		- {`\\a\b\`, `\\a\b`},
`97`		- {`\\folder\share\foo`, `\\folder\share\foo`},
`98`		- {`\\folder\share\foo\`, `\\folder\share\foo`},
`99`	`96`	`}`
`100`	`97`
`101`	`98`	`func TestClean(t *testing.T) {`