diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index 69d81672e..6ad224978 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -1986,10 +1986,11 @@ inline void hb_ot_map_t::apply (const Proxy &proxy,
 
     if (stage->pause_func)
     {
-      stage->pause_func (plan, font, buffer);
-      /* Refresh working buffer digest since buffer content
-       * might have changed. */
-      c.digest = buffer->digest ();
+      if (stage->pause_func (plan, font, buffer))
+      {
+	/* Refresh working buffer digest since buffer changed. */
+	c.digest = buffer->digest ();
+      }
     }
   }
 }
diff --git a/src/hb-ot-layout.hh b/src/hb-ot-layout.hh
index de06610cb..74f0e015f 100644
--- a/src/hb-ot-layout.hh
+++ b/src/hb-ot-layout.hh
@@ -552,7 +552,7 @@ _hb_glyph_info_clear_substituted (hb_glyph_info_t *info)
   info->glyph_props() &= ~(HB_OT_LAYOUT_GLYPH_PROPS_SUBSTITUTED);
 }
 
-static inline void
+static inline bool
 _hb_clear_substitution_flags (const hb_ot_shape_plan_t *plan HB_UNUSED,
 			      hb_font_t *font HB_UNUSED,
 			      hb_buffer_t *buffer)
@@ -561,6 +561,7 @@ _hb_clear_substitution_flags (const hb_ot_shape_plan_t *plan HB_UNUSED,
   unsigned int count = buffer->len;
   for (unsigned int i = 0; i < count; i++)
     _hb_glyph_info_clear_substituted (&info[i]);
+  return false;
 }
 
 
diff --git a/src/hb-ot-map.hh b/src/hb-ot-map.hh
index a7b5eec30..1255b21cc 100644
--- a/src/hb-ot-map.hh
+++ b/src/hb-ot-map.hh
@@ -78,7 +78,7 @@ struct hb_ot_map_t
     }
   };
 
-  typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
+  typedef bool (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);
 
   struct stage_map_t {
     unsigned int last_lookup; /* Cumulative */
diff --git a/src/hb-ot-shaper-arabic.cc b/src/hb-ot-shaper-arabic.cc
index ed2748b82..2332ae369 100644
--- a/src/hb-ot-shaper-arabic.cc
+++ b/src/hb-ot-shaper-arabic.cc
@@ -161,22 +161,23 @@ static const struct arabic_state_table_entry {
 };
 
 
-static void
+static bool
 arabic_fallback_shape (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer);
 
-static void
+static bool
 record_stch (const hb_ot_shape_plan_t *plan,
 	     hb_font_t *font,
 	     hb_buffer_t *buffer);
 
-static void
+static bool
 deallocate_buffer_var (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer)
 {
   HB_BUFFER_DEALLOCATE_VAR (buffer, arabic_shaping_action);
+  return false;
 }
 
 static void
@@ -412,19 +413,19 @@ setup_masks_arabic (const hb_ot_shape_plan_t *plan,
   setup_masks_arabic_plan (arabic_plan, buffer, plan->props.script);
 }
 
-static void
+static bool
 arabic_fallback_shape (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer)
 {
 #ifdef HB_NO_OT_SHAPER_ARABIC_FALLBACK
-  return;
+  return false;
 #endif
 
   const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
 
   if (!arabic_plan->do_fallback)
-    return;
+    return false;
 
 retry:
   arabic_fallback_plan_t *fallback_plan = arabic_plan->fallback_plan;
@@ -440,6 +441,7 @@ retry:
   }
 
   arabic_fallback_plan_shape (fallback_plan, font, buffer);
+  return true;
 }
 
 /*
@@ -450,14 +452,14 @@ retry:
  * marks can use it as well.
  */
 
-static void
+static bool
 record_stch (const hb_ot_shape_plan_t *plan,
 	     hb_font_t *font HB_UNUSED,
 	     hb_buffer_t *buffer)
 {
   const arabic_shape_plan_t *arabic_plan = (const arabic_shape_plan_t *) plan->data;
   if (!arabic_plan->has_stch)
-    return;
+    return false;
 
   /* 'stch' feature was just applied.  Look for anything that multiplied,
    * and record it for stch treatment later.  Note that rtlm, frac, etc
@@ -473,6 +475,7 @@ record_stch (const hb_ot_shape_plan_t *plan,
       info[i].arabic_shaping_action() = comp % 2 ? STCH_REPEATING : STCH_FIXED;
       buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH;
     }
+  return false;
 }
 
 static void
diff --git a/src/hb-ot-shaper-indic.cc b/src/hb-ot-shaper-indic.cc
index 1f6ae5237..d7cde140d 100644
--- a/src/hb-ot-shaper-indic.cc
+++ b/src/hb-ot-shaper-indic.cc
@@ -223,15 +223,15 @@ enum {
   INDIC_BASIC_FEATURES = INDIC_INIT, /* Don't forget to update this! */
 };
 
-static void
+static bool
 setup_syllables_indic (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer);
-static void
+static bool
 initial_reordering_indic (const hb_ot_shape_plan_t *plan,
 			  hb_font_t *font,
 			  hb_buffer_t *buffer);
-static void
+static bool
 final_reordering_indic (const hb_ot_shape_plan_t *plan,
 			hb_font_t *font,
 			hb_buffer_t *buffer);
@@ -413,7 +413,7 @@ setup_masks_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
     set_indic_properties (info[i]);
 }
 
-static void
+static bool
 setup_syllables_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		       hb_font_t *font HB_UNUSED,
 		       hb_buffer_t *buffer)
@@ -422,6 +422,7 @@ setup_syllables_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
   find_syllables_indic (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);
+  return false;
 }
 
 static int
@@ -981,25 +982,29 @@ initial_reordering_syllable_indic (const hb_ot_shape_plan_t *plan,
   }
 }
 
-static void
+static bool
 initial_reordering_indic (const hb_ot_shape_plan_t *plan,
 			  hb_font_t *font,
 			  hb_buffer_t *buffer)
 {
+  bool ret = false;
   if (!buffer->message (font, "start reordering indic initial"))
-    return;
+    return ret;
 
   update_consonant_positions_indic (plan, font, buffer);
-  hb_syllabic_insert_dotted_circles (font, buffer,
-				     indic_broken_cluster,
-				     I_Cat(DOTTEDCIRCLE),
-				     I_Cat(Repha),
-				     POS_END);
+  if (hb_syllabic_insert_dotted_circles (font, buffer,
+					 indic_broken_cluster,
+					 I_Cat(DOTTEDCIRCLE),
+					 I_Cat(Repha),
+					 POS_END))
+    ret = true;
 
   foreach_syllable (buffer, start, end)
     initial_reordering_syllable_indic (plan, font->face, buffer, start, end);
 
   (void) buffer->message (font, "end reordering indic initial");
+
+  return ret;
 }
 
 static void
@@ -1465,13 +1470,13 @@ final_reordering_syllable_indic (const hb_ot_shape_plan_t *plan,
 }
 
 
-static void
+static bool
 final_reordering_indic (const hb_ot_shape_plan_t *plan,
 			hb_font_t *font HB_UNUSED,
 			hb_buffer_t *buffer)
 {
   unsigned int count = buffer->len;
-  if (unlikely (!count)) return;
+  if (unlikely (!count)) return false;
 
   if (buffer->message (font, "start reordering indic final")) {
     foreach_syllable (buffer, start, end)
@@ -1481,6 +1486,8 @@ final_reordering_indic (const hb_ot_shape_plan_t *plan,
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category);
   HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position);
+
+  return false;
 }
 
 
diff --git a/src/hb-ot-shaper-khmer.cc b/src/hb-ot-shaper-khmer.cc
index d9795589f..019a28510 100644
--- a/src/hb-ot-shaper-khmer.cc
+++ b/src/hb-ot-shaper-khmer.cc
@@ -89,11 +89,11 @@ set_khmer_properties (hb_glyph_info_t &info)
   info.khmer_category() = (khmer_category_t) (type & 0xFFu);
 }
 
-static void
+static bool
 setup_syllables_khmer (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer);
-static void
+static bool
 reorder_khmer (const hb_ot_shape_plan_t *plan,
 	       hb_font_t *font,
 	       hb_buffer_t *buffer);
@@ -192,7 +192,7 @@ setup_masks_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
     set_khmer_properties (info[i]);
 }
 
-static void
+static bool
 setup_syllables_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		       hb_font_t *font HB_UNUSED,
 		       hb_buffer_t *buffer)
@@ -201,6 +201,7 @@ setup_syllables_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
   find_syllables_khmer (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);
+  return false;
 }
 
 
@@ -303,23 +304,27 @@ reorder_syllable_khmer (const hb_ot_shape_plan_t *plan,
   }
 }
 
-static void
+static bool
 reorder_khmer (const hb_ot_shape_plan_t *plan,
 	       hb_font_t *font,
 	       hb_buffer_t *buffer)
 {
+  bool ret = false;
   if (buffer->message (font, "start reordering khmer"))
   {
-    hb_syllabic_insert_dotted_circles (font, buffer,
-				       khmer_broken_cluster,
-				       K_Cat(DOTTEDCIRCLE),
-				       (unsigned) -1);
+    if (hb_syllabic_insert_dotted_circles (font, buffer,
+					   khmer_broken_cluster,
+					   K_Cat(DOTTEDCIRCLE),
+					   (unsigned) -1))
+      ret = true;
 
     foreach_syllable (buffer, start, end)
       reorder_syllable_khmer (plan, font->face, buffer, start, end);
     (void) buffer->message (font, "end reordering khmer");
   }
   HB_BUFFER_DEALLOCATE_VAR (buffer, khmer_category);
+
+  return ret;
 }
 
 
diff --git a/src/hb-ot-shaper-myanmar.cc b/src/hb-ot-shaper-myanmar.cc
index 1039bdfeb..90ccd2d6a 100644
--- a/src/hb-ot-shaper-myanmar.cc
+++ b/src/hb-ot-shaper-myanmar.cc
@@ -98,11 +98,11 @@ is_consonant_myanmar (const hb_glyph_info_t &info)
 }
 
 
-static void
+static bool
 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
 			 hb_font_t *font,
 			 hb_buffer_t *buffer);
-static void
+static bool
 reorder_myanmar (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font,
 		 hb_buffer_t *buffer);
@@ -150,7 +150,7 @@ setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
     set_myanmar_properties (info[i]);
 }
 
-static void
+static bool
 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
 			 hb_font_t *font HB_UNUSED,
 			 hb_buffer_t *buffer)
@@ -159,6 +159,7 @@ setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
   find_syllables_myanmar (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);
+  return false;
 }
 
 static int
@@ -318,16 +319,18 @@ reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
   }
 }
 
-static void
+static bool
 reorder_myanmar (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font,
 		 hb_buffer_t *buffer)
 {
+  bool ret = false;
   if (buffer->message (font, "start reordering myanmar"))
   {
-    hb_syllabic_insert_dotted_circles (font, buffer,
-				       myanmar_broken_cluster,
-				       M_Cat(DOTTEDCIRCLE));
+    if (hb_syllabic_insert_dotted_circles (font, buffer,
+					   myanmar_broken_cluster,
+					   M_Cat(DOTTEDCIRCLE)))
+      ret = true;
 
     foreach_syllable (buffer, start, end)
       reorder_syllable_myanmar (plan, font->face, buffer, start, end);
@@ -336,6 +339,8 @@ reorder_myanmar (const hb_ot_shape_plan_t *plan,
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_category);
   HB_BUFFER_DEALLOCATE_VAR (buffer, myanmar_position);
+
+  return ret;
 }
 
 
diff --git a/src/hb-ot-shaper-syllabic.cc b/src/hb-ot-shaper-syllabic.cc
index a8e0d8e8c..89226ae4a 100644
--- a/src/hb-ot-shaper-syllabic.cc
+++ b/src/hb-ot-shaper-syllabic.cc
@@ -29,7 +29,7 @@
 #include "hb-ot-shaper-syllabic.hh"
 
 
-void
+bool
 hb_syllabic_insert_dotted_circles (hb_font_t *font,
 				   hb_buffer_t *buffer,
 				   unsigned int broken_syllable_type,
@@ -38,13 +38,13 @@ hb_syllabic_insert_dotted_circles (hb_font_t *font,
 				   int dottedcircle_position)
 {
   if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
-    return;
+    return false;
   if (likely (!(buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_BROKEN_SYLLABLE)))
-    return;
+    return false;
 
   hb_codepoint_t dottedcircle_glyph;
   if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
-    return;
+    return false;
 
   hb_glyph_info_t dottedcircle = {0};
   dottedcircle.codepoint = 0x25CCu;
@@ -84,14 +84,16 @@ hb_syllabic_insert_dotted_circles (hb_font_t *font,
       (void) buffer->next_glyph ();
   }
   buffer->sync ();
+  return true;
 }
 
-HB_INTERNAL void
+HB_INTERNAL bool
 hb_syllabic_clear_var (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer)
 {
   HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
+  return false;
 }
 
 
diff --git a/src/hb-ot-shaper-syllabic.hh b/src/hb-ot-shaper-syllabic.hh
index e8a15bb48..f240ad1c2 100644
--- a/src/hb-ot-shaper-syllabic.hh
+++ b/src/hb-ot-shaper-syllabic.hh
@@ -30,7 +30,7 @@
 #include "hb-ot-shaper.hh"
 
 
-HB_INTERNAL void
+HB_INTERNAL bool
 hb_syllabic_insert_dotted_circles (hb_font_t *font,
 				   hb_buffer_t *buffer,
 				   unsigned int broken_syllable_type,
@@ -38,7 +38,7 @@ hb_syllabic_insert_dotted_circles (hb_font_t *font,
 				   int repha_category = -1,
 				   int dottedcircle_position = -1);
 
-HB_INTERNAL void
+HB_INTERNAL bool
 hb_syllabic_clear_var (const hb_ot_shape_plan_t *plan,
 		       hb_font_t *font,
 		       hb_buffer_t *buffer);
diff --git a/src/hb-ot-shaper-use.cc b/src/hb-ot-shaper-use.cc
index c40ec52f9..342aba123 100644
--- a/src/hb-ot-shaper-use.cc
+++ b/src/hb-ot-shaper-use.cc
@@ -89,19 +89,19 @@ use_other_features[] =
   HB_TAG('p','s','t','s'),
 };
 
-static void
+static bool
 setup_syllables_use (const hb_ot_shape_plan_t *plan,
 		     hb_font_t *font,
 		     hb_buffer_t *buffer);
-static void
+static bool
 record_rphf_use (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font,
 		 hb_buffer_t *buffer);
-static void
+static bool
 record_pref_use (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font,
 		 hb_buffer_t *buffer);
-static void
+static bool
 reorder_use (const hb_ot_shape_plan_t *plan,
 	     hb_font_t *font,
 	     hb_buffer_t *buffer);
@@ -293,7 +293,7 @@ setup_topographical_masks (const hb_ot_shape_plan_t *plan,
   }
 }
 
-static void
+static bool
 setup_syllables_use (const hb_ot_shape_plan_t *plan,
 		     hb_font_t *font HB_UNUSED,
 		     hb_buffer_t *buffer)
@@ -304,9 +304,10 @@ setup_syllables_use (const hb_ot_shape_plan_t *plan,
     buffer->unsafe_to_break (start, end);
   setup_rphf_mask (plan, buffer);
   setup_topographical_masks (plan, buffer);
+  return false;
 }
 
-static void
+static bool
 record_rphf_use (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font HB_UNUSED,
 		 hb_buffer_t *buffer)
@@ -314,7 +315,7 @@ record_rphf_use (const hb_ot_shape_plan_t *plan,
   const use_shape_plan_t *use_plan = (const use_shape_plan_t *) plan->data;
 
   hb_mask_t mask = use_plan->rphf_mask;
-  if (!mask) return;
+  if (!mask) return false;
   hb_glyph_info_t *info = buffer->info;
 
   foreach_syllable (buffer, start, end)
@@ -327,9 +328,10 @@ record_rphf_use (const hb_ot_shape_plan_t *plan,
 	break;
       }
   }
+  return false;
 }
 
-static void
+static bool
 record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		 hb_font_t *font HB_UNUSED,
 		 hb_buffer_t *buffer)
@@ -346,6 +348,7 @@ record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	break;
       }
   }
+  return false;
 }
 
 static inline bool
@@ -438,17 +441,19 @@ reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
   }
 }
 
-static void
+static bool
 reorder_use (const hb_ot_shape_plan_t *plan,
 	     hb_font_t *font,
 	     hb_buffer_t *buffer)
 {
+  bool ret = false;
   if (buffer->message (font, "start reordering USE"))
   {
-    hb_syllabic_insert_dotted_circles (font, buffer,
-				       use_broken_cluster,
-				       USE(B),
-				       USE(R));
+    if (hb_syllabic_insert_dotted_circles (font, buffer,
+					   use_broken_cluster,
+					   USE(B),
+					   USE(R)))
+      ret = true;
 
     foreach_syllable (buffer, start, end)
       reorder_syllable_use (buffer, start, end);
@@ -457,6 +462,8 @@ reorder_use (const hb_ot_shape_plan_t *plan,
   }
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
+
+  return ret;
 }