[vala] Improve CamelCase to lower_case transformation

[Jürg Billeter <juergbi src gnome org>]

commit bef8df5b091023484c3664b2f76fa713fca07043
Author: Jürg Billeter <j bitron ch>
Date:   Sat Aug 1 18:10:45 2009 +0200

    Improve CamelCase to lower_case transformation
    
    Fixes bug 585718.

 vala/valasymbol.vala |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/vala/valasymbol.vala b/vala/valasymbol.vala
index ca54bd6..36d32c5 100644
--- a/vala/valasymbol.vala
+++ b/vala/valasymbol.vala
@@ -221,6 +221,11 @@ public abstract class Vala.Symbol : CodeNode {
 	 * @return           the specified string converted to lower case
 	 */
 	public static string camel_case_to_lower_case (string camel_case) {
+		if ("_" in camel_case) {
+			// do not insert additional underscores if input is not real camel case
+			return camel_case.down ();
+		}
+
 		var result_builder = new StringBuilder ("");
 
 		weak string i = camel_case;