relaxed config scanner mode

- does not fail on MySQL 'prompt' config

go/base/context.go

@@ -18,6 +18,7 @@ import (
 	"github.com/github/gh-ost/go/sql"
 
 	"gopkg.in/gcfg.v1"
+	gcfgscanner "gopkg.in/gcfg.v1/scanner"
 )
 
 // RowsEstimateMethod is the type of row number estimation
@@ -507,6 +508,7 @@ func (this *MigrationContext) ReadConfigFile() error {
 		return nil
 	}
 	gcfg.RelaxedParserMode = true
+	gcfgscanner.RelaxedScannerMode = true
 	if err := gcfg.ReadFileInto(&this.config, this.ConfigFile); err != nil {
 		return err
 	}

vendor/gopkg.in/gcfg.v1/scanner/scanner.go

@@ -16,12 +16,12 @@ import (
 	"path/filepath"
 	"unicode"
 	"unicode/utf8"
-)
 
-import (
 	"gopkg.in/gcfg.v1/token"
 )
 
+var RelaxedScannerMode = false
+
 // An ErrorHandler may be provided to Scanner.Init. If a syntax error is
 // encountered and a handler was installed, the handler is called with a
 // position and an error message. The position points to the beginning of
@@ -231,7 +231,7 @@ loop:
 				hasCR = true
 				s.next()
 			}
-			if s.ch != '\n' {
+			if s.ch != '\n' && !RelaxedScannerMode {
 				s.error(offs, "unquoted '\\' must be followed by new line")
 				break loop
 			}