path/filepath: change IsAbs("NUL") to return true
This CL changes IsAbs to return true for "NUL" and other Windows
reserved filenames (search
https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
for NUL for details). os.Open("NUL") and os.Stat("NUL") work
regardless of what current directory is, and it is mistake to join
"NUL" with current directory when building full path. Changing
IsAbs("NUL") to return true fixes that mistake.
Fixes #28035
Change-Id: Ife8f8aee48400702613ede8fc6834fd43e6e0f03
Reviewed-on: https://go-review.googlesource.com/c/145220
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/cmd/go/testdata/script/test_devnull.txt b/src/cmd/go/testdata/script/test_devnull.txt
new file mode 100644
index 0000000..c414e59
--- /dev/null
+++ b/src/cmd/go/testdata/script/test_devnull.txt
@@ -0,0 +1,13 @@
+# go test -c -o NUL
+# should work (see golang.org/issue/28035).
+cd x
+go test -o=$devnull -c
+! exists x.test$exe
+
+-- x/x_test.go --
+package x_test
+import (
+ "testing"
+)
+func TestNUL(t *testing.T) {
+}
diff --git a/src/path/filepath/path_test.go b/src/path/filepath/path_test.go
index eddae47..3434ea2 100644
--- a/src/path/filepath/path_test.go
+++ b/src/path/filepath/path_test.go
@@ -751,6 +751,11 @@
for _, test := range isabstests {
tests = append(tests, IsAbsTest{"c:" + test.path, test.isAbs})
}
+ // Test reserved names.
+ tests = append(tests, IsAbsTest{os.DevNull, true})
+ tests = append(tests, IsAbsTest{"NUL", true})
+ tests = append(tests, IsAbsTest{"nul", true})
+ tests = append(tests, IsAbsTest{"CON", true})
} else {
tests = isabstests
}
diff --git a/src/path/filepath/path_windows.go b/src/path/filepath/path_windows.go
index 6a144d9..445c868 100644
--- a/src/path/filepath/path_windows.go
+++ b/src/path/filepath/path_windows.go
@@ -13,8 +13,34 @@
return c == '\\' || c == '/'
}
+// reservedNames lists reserved Windows names. Search for PRN in
+// https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+// for details.
+var reservedNames = []string{
+ "CON", "PRN", "AUX", "NUL",
+ "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9",
+ "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
+}
+
+// isReservedName returns true, if path is Windows reserved name.
+// See reservedNames for the full list.
+func isReservedName(path string) bool {
+ if len(path) == 0 {
+ return false
+ }
+ for _, reserved := range reservedNames {
+ if strings.EqualFold(path, reserved) {
+ return true
+ }
+ }
+ return false
+}
+
// IsAbs reports whether the path is absolute.
func IsAbs(path string) (b bool) {
+ if isReservedName(path) {
+ return true
+ }
l := volumeNameLen(path)
if l == 0 {
return false
