fix: SetLogger via klog.SetLogger will output an unexpected newline

klog always adds a newline to the msg. klog will work fine without klog.

Set logr with klog.SetLogger, and klog will also pass the msg with the newline added to logr, which will result in an accidental newline being added.

step1: klog.Info("hello world")
step2: msg = msg + "\n"
step3: stdout.W(msg) or logr.Info(msg[:len(msg)-1])

fix #370

Signed-off-by: aimuz <mr.imuz@gmail.com>

examples/flushing/.gitignore

@@ -0,0 +1 @@
+myfile.log

klog.go

@@ -873,6 +873,9 @@ func (l *loggingT) output(s severity.Severity, logger *logWriter, buf *buffer.Bu
 		if logger.writeKlogBuffer != nil {
 			logger.writeKlogBuffer(data)
 		} else {
+			if len(data) > 0 && data[len(data)-1] == '\n' {
+				data = data[:len(data)-1]
+			}
 			// TODO: set 'severity' and caller information as structured log info
 			// keysAndValues := []interface{}{"severity", severityName[s], "file", file, "line", line}
 			if s == severity.ErrorLog {

klog_test.go

@@ -1484,13 +1484,13 @@ func TestInfoWithLogr(t *testing.T) {
 		msg: "foo",
 		expected: testLogrEntry{
 			severity: severity.InfoLog,
-			msg:      "foo\n",
+			msg:      "foo",
 		},
 	}, {
 		msg: "",
 		expected: testLogrEntry{
 			severity: severity.InfoLog,
-			msg:      "\n",
+			msg:      "",
 		},
 	}}
 

test/zapr.go

@@ -171,22 +171,22 @@ I output.go:<LINE>] "odd WithValues" keyWithoutValue="(MISSING)"
 
 		// klog.Info
 		`I output.go:<LINE>] "helloworld\n"
-`: `{"caller":"test/output.go:<LINE>","msg":"helloworld\n","v":0}
+`: `{"caller":"test/output.go:<LINE>","msg":"helloworld","v":0}
 `,
 
 		// klog.Infoln
 		`I output.go:<LINE>] "hello world\n"
-`: `{"caller":"test/output.go:<LINE>","msg":"hello world\n","v":0}
+`: `{"caller":"test/output.go:<LINE>","msg":"hello world","v":0}
 `,
 
 		// klog.Error
 		`E output.go:<LINE>] "helloworld\n"
-`: `{"caller":"test/output.go:<LINE>","msg":"helloworld\n"}
+`: `{"caller":"test/output.go:<LINE>","msg":"helloworld"}
 `,
 
 		// klog.Errorln
 		`E output.go:<LINE>] "hello world\n"
-`: `{"caller":"test/output.go:<LINE>","msg":"hello world\n"}
+`: `{"caller":"test/output.go:<LINE>","msg":"hello world"}
 `,
 
 		// klog.ErrorS
@@ -201,12 +201,12 @@ I output.go:<LINE>] "odd WithValues" keyWithoutValue="(MISSING)"
 
 		// klog.V(1).Info
 		`I output.go:<LINE>] "hellooneworld\n"
-`: `{"caller":"test/output.go:<LINE>","msg":"hellooneworld\n","v":1}
+`: `{"caller":"test/output.go:<LINE>","msg":"hellooneworld","v":1}
 `,
 
 		// klog.V(1).Infoln
 		`I output.go:<LINE>] "hello one world\n"
-`: `{"caller":"test/output.go:<LINE>","msg":"hello one world\n","v":1}
+`: `{"caller":"test/output.go:<LINE>","msg":"hello one world","v":1}
 `,
 
 		// klog.V(1).ErrorS