liberasurecode_backend_lookup_id now returns EC_BACKENDS_MAX, asnewapi

opposed to -1, when it can not locate the specified backend (-1
was a non-sensical return value since the function signature
called for a type of ec_backend_id_t). NOTE: with this change we
now successfully build and tests pass on OS X with clang.

2 files changed, 7 insertions, 7 deletions

diff --git a/src/erasurecode.c b/src/erasurecode.c
index b376568..0d7e563 100644
--- a/src/erasurecode.c
+++ b/src/erasurecode.c
@@ -81,7 +81,7 @@ ec_backend_t liberasurecode_backend_lookup_by_name(const char *name)
 ec_backend_id_t liberasurecode_backend_lookup_id(const char *name)
 {
     if (NULL == name)
-        return -1;
+        return EC_BACKENDS_MAX;
     int b = 0;
 
     for (b = 0; ec_backends_supported[b]; ++b) {
@@ -90,7 +90,7 @@ ec_backend_id_t liberasurecode_backend_lookup_id(const char *name)
             return backend->common.id;
     }
 
-    return -1;
+    return EC_BACKENDS_MAX;
 }
 
 /* =~=*=~==~=*=~==~=*=~= EC backend instance management =~=*=~==~=*=~==~=*= */
@@ -313,7 +313,7 @@ int liberasurecode_instance_create(const char *backend_name,
         return -1;
 
     ec_backend_id_t id = liberasurecode_backend_lookup_id(backend_name);
-    if (-1 == id)
+    if (EC_BACKENDS_MAX == id)
         return -EBACKENDNOTSUPP;
 
     /* Allocate memory for ec_backend instance */
diff --git a/test/liberasurecode_test.c b/test/liberasurecode_test.c
index 6b6bfd4..e81c111 100644
--- a/test/liberasurecode_test.c
+++ b/test/liberasurecode_test.c
@@ -907,10 +907,10 @@ static void test_backend_lookup_by_id()
     int i =0, num_backends;
     const char **supported_ec_backends =
         liberasurecode_supported_backends(&num_backends);
-    assert(liberasurecode_backend_lookup_id(null_name) == -1);
-    assert(liberasurecode_backend_lookup_id(empty_name) == -1);
-    assert(liberasurecode_backend_lookup_id(white_space_name) == -1);
-    assert(liberasurecode_backend_lookup_id(missing_name) == -1);
+    assert(liberasurecode_backend_lookup_id(null_name) == EC_BACKENDS_MAX);
+    assert(liberasurecode_backend_lookup_id(empty_name) == EC_BACKENDS_MAX);
+    assert(liberasurecode_backend_lookup_id(white_space_name) == EC_BACKENDS_MAX);
+    assert(liberasurecode_backend_lookup_id(missing_name) == EC_BACKENDS_MAX);
     for (i = 0; i < num_backends; i++) {
         assert(liberasurecode_backend_lookup_id(supported_ec_backends[i]) == i);
     }