[subset] Rename constructor to hb_subset_input_create_or_fail()

To signify that unlike rest of library, returns nullptr on failure.

src/hb-subset-input.cc

@@ -29,19 +29,17 @@
 #include "hb-set-private.hh"
 
 /**
- * hb_subset_input_create:
+ * hb_subset_input_create_or_fail:
  *
  * Return value: New subset input.
  *
  * Since: 1.8.0
  **/
 hb_subset_input_t *
-hb_subset_input_create (void)
+hb_subset_input_create_or_fail (void)
 {
   hb_subset_input_t *input = hb_object_create<hb_subset_input_t>();
 
-  /* Unlike libharfbuzz, in this lib we return nullptr
-   * in case of allocation failure. */
   if (unlikely (!input))
     return nullptr;
 

src/hb-subset.h

@@ -54,7 +54,7 @@ hb_subset_profile_destroy (hb_subset_profile_t *profile);
 typedef struct hb_subset_input_t hb_subset_input_t;
 
 HB_EXTERN hb_subset_input_t *
-hb_subset_input_create (void);
+hb_subset_input_create_or_fail (void);
 
 HB_EXTERN hb_subset_input_t *
 hb_subset_input_reference (hb_subset_input_t *subset_input);

test/api/test-subset-glyf.c

@@ -95,9 +95,10 @@ test_subset_glyf (void)
   hb_blob_t *glyf_expected_blob;
   hb_blob_t *glyf_actual_blob;
   hb_subset_profile_t *profile = hb_subset_profile_create();
-  hb_subset_input_t *input = hb_subset_input_create ();
+  hb_subset_input_t *input = hb_subset_input_create_or_fail ();
   hb_set_t *codepoints = hb_set_reference (hb_subset_input_unicode_set (input));
 
+  g_assert (input);
   g_assert (face_abc);
   g_assert (face_ac);
 

test/api/test-subset.c

@@ -43,12 +43,15 @@ test_subset (void)
   hb_face_t *face = hb_face_create(font_blob, 0);
 
   hb_subset_profile_t *profile = hb_subset_profile_create();
-  hb_subset_input_t *input = hb_subset_input_create ();
+  hb_subset_input_t *input = hb_subset_input_create_or_fail ();
 
   hb_face_t *out_face = hb_subset(face, profile, input);
+  hb_blob_t *output;
+
+  g_assert (input);
   g_assert(out_face);
   g_assert(out_face != hb_face_get_empty ());
-  hb_blob_t *output = hb_face_reference_blob (out_face);
+  output = hb_face_reference_blob (out_face);
 
   unsigned int output_length;
   const char *output_data = hb_blob_get_data(output, &output_length);

util/hb-subset.cc

@@ -43,7 +43,7 @@ struct subset_consumer_t
              const font_options_t *font_opts)
   {
     font = hb_font_reference (font_opts->get_font ());
-    input = hb_subset_input_create ();
+    input = hb_subset_input_create_or_fail ();
   }
 
   void consume_line (const char   *text,