fix: don't print to stdout when initializing console fails on Windows

muesli · muesli · commit 7b7885aa1ac2 · 2023-03-10T11:12:25.000+01:00
When stdin/err/out are redirected, console mode can't be changed.
That's often expected &amp; acceptable however, so we shouldn't print
errors to stdout.

Signed-off-by: Christian Muehlhaeuser &lt;muesli@gmail.com&gt;
diff --git a/console_windows.go b/console_windows.go
@@ -30,6 +30,10 @@ var (
 )
 
 func (m *master) initStdios() {
+	// Note: We discard console mode warnings, because in/out can be redirected.
+	//
+	// TODO: Investigate opening CONOUT$/CONIN$ to handle this correctly
+
 	m.in = windows.Handle(os.Stdin.Fd())
 	if err := windows.GetConsoleMode(m.in, &m.inMode); err == nil {
 		// Validate that windows.ENABLE_VIRTUAL_TERMINAL_INPUT is supported, but do not set it.
@@ -39,8 +43,6 @@ func (m *master) initStdios() {
 		// Unconditionally set the console mode back even on failure because SetConsoleMode
 		// remembers invalid bits on input handles.
 		windows.SetConsoleMode(m.in, m.inMode)
-	} else {
-		fmt.Printf("failed to get console mode for stdin: %v\n", err)
 	}
 
 	m.out = windows.Handle(os.Stdout.Fd())
@@ -50,8 +52,6 @@ func (m *master) initStdios() {
 		} else {
 			windows.SetConsoleMode(m.out, m.outMode)
 		}
-	} else {
-		fmt.Printf("failed to get console mode for stdout: %v\n", err)
 	}
 
 	m.err = windows.Handle(os.Stderr.Fd())
@@ -61,8 +61,6 @@ func (m *master) initStdios() {
 		} else {
 			windows.SetConsoleMode(m.err, m.errMode)
 		}
-	} else {
-		fmt.Printf("failed to get console mode for stderr: %v\n", err)
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -30,6 +30,10 @@ var (`
`30`	`30`	`)`
`31`	`31`
`32`	`32`	`func (m *master) initStdios() {`
	`33`	`+ // Note: We discard console mode warnings, because in/out can be redirected.`
	`34`	`+ //`
	`35`	`+ // TODO: Investigate opening CONOUT$/CONIN$ to handle this correctly`
	`36`	`+`
`33`	`37`	`m.in = windows.Handle(os.Stdin.Fd())`
`34`	`38`	`if err := windows.GetConsoleMode(m.in, &m.inMode); err == nil {`
`35`	`39`	`// Validate that windows.ENABLE_VIRTUAL_TERMINAL_INPUT is supported, but do not set it.`
`@@ -39,8 +43,6 @@ func (m *master) initStdios() {`
`39`	`43`	`// Unconditionally set the console mode back even on failure because SetConsoleMode`
`40`	`44`	`// remembers invalid bits on input handles.`
`41`	`45`	`windows.SetConsoleMode(m.in, m.inMode)`
`42`		`- } else {`
`43`		`- fmt.Printf("failed to get console mode for stdin: %v\n", err)`
`44`	`46`	`}`
`45`	`47`
`46`	`48`	`m.out = windows.Handle(os.Stdout.Fd())`
`@@ -50,8 +52,6 @@ func (m *master) initStdios() {`
`50`	`52`	`} else {`
`51`	`53`	`windows.SetConsoleMode(m.out, m.outMode)`
`52`	`54`	`}`
`53`		`- } else {`
`54`		`- fmt.Printf("failed to get console mode for stdout: %v\n", err)`
`55`	`55`	`}`
`56`	`56`
`57`	`57`	`m.err = windows.Handle(os.Stderr.Fd())`
`@@ -61,8 +61,6 @@ func (m *master) initStdios() {`
`61`	`61`	`} else {`
`62`	`62`	`windows.SetConsoleMode(m.err, m.errMode)`
`63`	`63`	`}`
`64`		`- } else {`
`65`		`- fmt.Printf("failed to get console mode for stderr: %v\n", err)`
`66`	`64`	`}`
`67`	`65`	`}`
`68`	`66`