commit eb0bf3ae6688b7e98a706df2ad2714c071d77e22
author Behdad Esfahbod <behdad@behdad.org> Wed Aug 06 15:36:41 2014 -0400
committer Behdad Esfahbod <behdad@behdad.org> Thu Apr 09 19:16:57 2015 -0700
tree 81d0d6e190cf205fd7566236c5925056f942bd2a
parent e8fd83932a75cfbaa4638a757868915ebfac3c1f

Relax inert checks

Previously, when creating an object from inert inputs (eg:
"hb_font_create(hb_face_get_empty())") we returned the inert
empty object.  This is not helpful as there are legitimate
usecases to do that.

We now never return the inert object unless allocation failed.

Tests are revised to reflect.

src/hb-face.cc

diff --git a/src/hb-face.cc b/src/hb-face.cc
index 9348af7..f38f047 100644
--- a/src/hb-face.cc
+++ b/src/hb-face.cc
@@ -165,8 +165,8 @@
 {
   hb_face_t *face;
 
-  if (unlikely (!blob || !hb_blob_get_length (blob)))
-    return hb_face_get_empty ();
+  if (unlikely (!blob))
+    blob = hb_blob_get_empty ();
 
   hb_face_for_data_closure_t *closure = _hb_face_for_data_closure_create (OT::Sanitizer<OT::OpenTypeFontFile>::sanitize (hb_blob_reference (blob)), index);
 

src/hb-font.cc

diff --git a/src/hb-font.cc b/src/hb-font.cc
index d42db59..3df41bd 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -854,8 +854,6 @@
 
   if (unlikely (!face))
     face = hb_face_get_empty ();
-  if (unlikely (hb_object_is_inert (face)))
-    return hb_font_get_empty ();
   if (!(font = hb_object_create<hb_font_t> ()))
     return hb_font_get_empty ();
 
@@ -880,7 +878,7 @@
 hb_font_create_sub_font (hb_font_t *parent)
 {
   if (unlikely (!parent))
-    return hb_font_get_empty ();
+    parent = hb_font_get_empty ();
 
   hb_font_t *font = hb_font_create (parent->face);
 

src/hb-shape-plan.cc

diff --git a/src/hb-shape-plan.cc b/src/hb-shape-plan.cc
index 2166173..4ccf90e 100644
--- a/src/hb-shape-plan.cc
+++ b/src/hb-shape-plan.cc
@@ -126,7 +126,7 @@
 
   if (unlikely (!face))
     face = hb_face_get_empty ();
-  if (unlikely (!props || hb_object_is_inert (face)))
+  if (unlikely (!props))
     return hb_shape_plan_get_empty ();
   if (num_user_features && !(features = (hb_feature_t *) malloc (num_user_features * sizeof (hb_feature_t))))
     return hb_shape_plan_get_empty ();
@@ -294,7 +294,6 @@
 		  shape_plan->shaper_func);
 
   if (unlikely (hb_object_is_inert (shape_plan) ||
-		hb_object_is_inert (font) ||
 		hb_object_is_inert (buffer)))
     return false;
 
@@ -453,6 +452,10 @@
 
   hb_shape_plan_t *shape_plan = hb_shape_plan_create (face, props, user_features, num_user_features, shaper_list);
 
+  /* Don't add to the cache if face is inert. */
+  if (unlikely (hb_object_is_inert (face)))
+    return shape_plan;
+
   /* Don't add the plan to the cache if there were user features with non-global ranges */
 
   if (hb_non_global_user_features_present (user_features, num_user_features))