Consolidate two duplicate conditional strdup wrappers to strdup_if

- Convert callers in prototype.c and library.c
- Current placement in library.c is somewhat arbitrary.  There
  currently doesn't seem to be a more suitable place.
- The behavior subtly changed: in case of failure, RET is now
  unaffected.

1 files changed, 6 insertions, 1 deletions

diff --git a/common.h b/common.h
index 637f041..a53c5db 100644
--- a/common.h
+++ b/common.h
@@ -1,6 +1,6 @@
 /*
  * This file is part of ltrace.
- * Copyright (C) 2011,2012 Petr Machata, Red Hat Inc.
+ * Copyright (C) 2011,2012,2013 Petr Machata, Red Hat Inc.
  * Copyright (C) 2010 Joe Damato
  * Copyright (C) 2009 Juan Cespedes
  *
@@ -66,4 +66,9 @@ struct library_symbol;
 int format_argument(FILE *stream, struct value *value,
 		    struct value_dict *arguments);
 
+/* Set *RET to either a duplicate of STR (if WHETHER), or STR
+ * (otherwise).  Return 0 on success or a negative value on failure.
+ * The duplication is not done if STR is NULL.  */
+int strdup_if(const char **ret, const char *str, int whether);
+
 #endif