do not add a '~' when filename is not truncated

This fixes an off-by-one when the filename length exactly matches our
size limit. As an example, today if the filename size limit is one
character and the filename is named "a", it will be incorrectly
formatted as "~a" despite no truncation occuring.

processor/formatters.go

@@ -931,7 +931,7 @@ func unicodeAwareTrim(tmp string, size int) string {
 	// iterate all the runes so we can cut off correctly and get the correct length
 	r := []rune(tmp)
 
-	if len(r) >= size {
+	if len(r) > size {
 		for runewidth.StringWidth(tmp) > size {
 			// remove character one at a time till we get the length we want
 			tmp = string([]rune(tmp)[1:])

processor/formatters_test.go

@@ -1392,6 +1392,14 @@ func TestUnicodeAwareTrimAscii(t *testing.T) {
 	}
 }
 
+func TestUnicodeAwareTrimExactSizeAscii(t *testing.T) {
+	tmp := "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.md"
+	res := unicodeAwareTrim(tmp, len(tmp))
+	if res != tmp {
+		t.Errorf("expected %s got %s", tmp, res)
+	}
+}
+
 func TestUnicodeAwareTrimUnicode(t *testing.T) {
 	tmp := "中文中文中文中文中文中文中文中文中文中文中文中文中文中文中文中文.md"
 	res := unicodeAwareTrim(tmp, shortFormatFileTruncate)