hide provider crashes from panicwrap when logging

When logging is turned on, panicwrap will still see provider crashes and
falsely report them as core crashes, hiding the formatted provider
error. We can trick panicwrap by slightly obfuscating the error line.

internal/logging/panic.go

@@ -172,11 +172,22 @@ func (l *logPanicWrapper) Debug(msg string, args ...interface{}) {
 	// output if this is the start of the traceback. An occasional false
 	// positive shouldn't be a big deal, since this is only retrieved after an
 	// error of some sort.
-	l.inPanic = l.inPanic || strings.HasPrefix(msg, "panic: ") || strings.HasPrefix(msg, "fatal error: ")
+
+	panicPrefix := strings.HasPrefix(msg, "panic: ") || strings.HasPrefix(msg, "fatal error: ")
+
+	l.inPanic = l.inPanic || panicPrefix
 
 	if l.inPanic && l.panicRecorder != nil {
 		l.panicRecorder(msg)
 	}
 
+	// If we have logging turned on, we need to prevent panicwrap from seeing
+	// this as a core panic. This can be done by obfuscating the panic error
+	// line.
+	if panicPrefix {
+		colon := strings.Index(msg, ":")
+		msg = strings.ToUpper(msg[:colon]) + msg[colon:]
+	}
+
 	l.Logger.Debug(msg, args...)
 }

internal/logging/panic_test.go

@@ -1,9 +1,12 @@
 package logging
 
 import (
+	"bytes"
 	"fmt"
 	"strings"
 	"testing"
+
+	"github.com/hashicorp/go-hclog"
 )
 
 func TestPanicRecorder(t *testing.T) {
@@ -49,3 +52,31 @@ func TestPanicLimit(t *testing.T) {
 		}
 	}
 }
+
+func TestLogPanicWrapper(t *testing.T) {
+	var buf bytes.Buffer
+	logger := hclog.NewInterceptLogger(&hclog.LoggerOptions{
+		Name:        "test",
+		Level:       hclog.Debug,
+		Output:      &buf,
+		DisableTime: true,
+	})
+
+	wrapped := (&logPanicWrapper{
+		Logger: logger,
+	}).Named("test")
+
+	wrapped.Debug("panic: invalid foo of bar")
+	wrapped.Debug("\tstack trace")
+
+	expected := `[DEBUG] test.test: PANIC: invalid foo of bar
+[DEBUG] test.test: 	stack trace
+`
+
+	got := buf.String()
+
+	if expected != got {
+		t.Fatalf("Expected:\n%q\nGot:\n%q", expected, got)
+	}
+
+}