Patch for testing.go to align multi-line log output of tests. Makes it easier to read and copy and paste

testing.go.diff

--- a/src/pkg/testing/testing.go  Sun Dec 30 12:01:53 2012 -0500
+++ b/src/pkg/testing/testing.go	Mon Jan 07 11:43:25 2013 +0000
@@ -91,6 +91,7 @@
 	"strings"
 	"sync"
 	"time"
+	"unicode/utf8"
 )
 
 var (
@@ -157,21 +158,23 @@
 		line = 1
 	}
 	buf := new(bytes.Buffer)
-	fmt.Fprintf(buf, "%s:%d: ", file, line)
+	source := fmt.Sprintf("%s:%d: ", file, line)
+	buf.WriteString(source)
 
 	lines := strings.Split(s, "\n")
 	if l := len(lines); l > 1 && lines[l-1] == "" {
 		lines = lines[:l-1]
 	}
+
+	// Round up the number of tabs required and add one to match first line
+	tabs := ((utf8.RuneCountInString(source) + 7) / 8) + 1
+	align := "\n" + strings.Repeat("\t", tabs)
 	for i, line := range lines {
-		if i > 0 {
-			buf.WriteByte('\n')
-		}
-		// Every line is indented at least one tab.
-		buf.WriteByte('\t')
-		if i > 0 {
-			// Second and subsequent lines are indented an extra tab.
-			buf.WriteByte('\t')
+		switch {
+		case i == 0:
+			buf.WriteByte('\t') // First line is indented at least one tab
+		case i > 0:
+			buf.WriteString(align) // Subsequent lines are aligned with the first
 		}
 		buf.WriteString(line)
 	}