Tracker: search for the localized decimal separator

Now that string_for_size return localized numbers, we can't assume the
decimal separator is a dot.

Fixes: #18900
Change-Id: I872d75b0e9e4eb5d085e04bfd4e8c26101a5b1b3
Reviewed-on: https://review.haiku-os.org/c/haiku/+/7671
Reviewed-by: waddlesplash <[email protected]>
Reviewed-by: Adrien Destugues <[email protected]>
Tested-by: Commit checker robot <[email protected]>

src/kits/tracker/WidgetAttributeText.cpp

@@ -50,6 +50,7 @@ All rights reserved.
 #include <Debug.h>
 #include <Locale.h>
 #include <NodeInfo.h>
+#include <NumberFormat.h>
 #include <Path.h>
 #include <StringFormat.h>
 #include <StringForSize.h>
@@ -102,15 +103,12 @@ TruncFileSizeBase(BString* outString, int64 value, const View* view,
 	} else {
 		// strip off an insignificant zero so we don't get readings
 		// such as 1.00
-		char* period = 0;
-		for (char* tmp = const_cast<char*>(buffer.String()); *tmp != '\0'; tmp++) {
-			if (*tmp == '.')
-				period = tmp;
-		}
-		if (period && period[1] && period[2] == '0') {
-			// move the rest of the string over the insignificant zero
-			for (char* tmp = &period[2]; *tmp; tmp++)
-				*tmp = tmp[1];
+		BNumberFormat numberFormat;
+		BString separator(numberFormat.GetSeparator(B_DECIMAL_SEPARATOR));
+		if (!separator.IsEmpty()) {
+			int32 position = buffer.FindFirst(separator);
+			if (position != B_ERROR && buffer.ByteAt(position + 2) == '0')
+				buffer.Remove(position + 2, 1);
 		}
 		float resultWidth = view->StringWidth(buffer);
 		if (resultWidth <= width) {