Buflib: Clarification about invalid handles

* Enhance allocation function comments to better state the return value and what an invalid value is
* Change clients to check for "< 0" instead of "<= 0" or "== 0"
* Return -1 or -2 depending on the exact failure in buflib_alloc_ex.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30469 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 2 insertions, 2 deletions

diff --git a/firmware/buflib.c b/firmware/buflib.c
index f7ef35ea8b..7c5f3d208e 100644
--- a/firmware/buflib.c
+++ b/firmware/buflib.c
@@ -425,7 +425,7 @@ handle_alloc:
                     goto handle_alloc;
                 }
             }
-            return 0;
+            return -1;
         }
     }
 
@@ -471,7 +471,7 @@ buffer_alloc:
         } else {
             handle->val=1;
             handle_free(ctx, handle);
-            return 0;
+            return -2;
         }
     }