2 files changed, 51 insertions, 0 deletions

diff --git a/src/w32font.c b/src/w32font.c
index eff1a78937a..37df1bc43c0 100644
--- a/src/w32font.c
+++ b/src/w32font.c
@@ -285,18 +285,25 @@ static Lisp_Object
 w32font_list_family (struct frame *f)
 {
   Lisp_Object list = Qnil;
+  Lisp_Object prev_quit = Vinhibit_quit;
   LOGFONT font_match_pattern;
   HDC dc;
 
   memset (&font_match_pattern, 0, sizeof (font_match_pattern));
   font_match_pattern.lfCharSet = DEFAULT_CHARSET;
 
+  /* Prevent quitting while EnumFontFamiliesEx runs and conses the
+     list it will return.  That's because get_frame_dc acquires the
+     critical section, so we cannot quit before we release it in
+     release_frame_dc.  */
+  Vinhibit_quit = Qt;
   dc = get_frame_dc (f);
 
   EnumFontFamiliesEx (dc, &font_match_pattern,
                       (FONTENUMPROC) add_font_name_to_list,
                       (LPARAM) &list, 0);
   release_frame_dc (f, dc);
+  Vinhibit_quit = prev_quit;
 
   return list;
 }
@@ -434,6 +441,7 @@ w32font_text_extents (struct font *font, unsigned *code,
   WORD *wcode;
   SIZE size;
   bool first;
+  Lisp_Object prev_quit = Vinhibit_quit;
 
   struct w32font_info *w32_font = (struct w32font_info *) font;
 
@@ -480,6 +488,12 @@ w32font_text_extents (struct font *font, unsigned *code,
                  is updated to pass in a frame.  */
               f = XFRAME (selected_frame);
 
+              /* Prevent quitting while EnumFontFamiliesEx runs and
+                 conses the list it will return.  That's because
+                 get_frame_dc acquires the critical section, so we
+                 cannot quit before we release it in release_frame_dc.  */
+              prev_quit = Vinhibit_quit;
+              Vinhibit_quit = Qt;
               dc = get_frame_dc (f);
               old_font = SelectObject (dc, w32_font->hfont);
             }
@@ -520,6 +534,7 @@ w32font_text_extents (struct font *font, unsigned *code,
           /* Restore state and release DC.  */
           SelectObject (dc, old_font);
           release_frame_dc (f, dc);
+          Vinhibit_quit = prev_quit;
         }
       return;
     }
@@ -556,6 +571,12 @@ w32font_text_extents (struct font *font, unsigned *code,
          frame.  */
       f = XFRAME (selected_frame);
 
+      /* Prevent quitting while EnumFontFamiliesEx runs and conses the
+         list it will return.  That's because get_frame_dc acquires
+         the critical section, so we cannot quit before we release it
+         in release_frame_dc.  */
+      prev_quit = Vinhibit_quit;
+      Vinhibit_quit = Qt;
       dc = get_frame_dc (f);
       old_font = SelectObject (dc, w32_font->hfont);
     }
@@ -586,6 +607,7 @@ w32font_text_extents (struct font *font, unsigned *code,
   /* Restore state and release DC.  */
   SelectObject (dc, old_font);
   release_frame_dc (f, dc);
+  Vinhibit_quit = prev_quit;
 }
 
 /* w32 implementation of draw for font backend.
@@ -812,12 +834,20 @@ w32font_list_internal (struct frame *f, Lisp_Object font_spec,
     }
   else
     {
+      Lisp_Object prev_quit = Vinhibit_quit;
+
+      /* Prevent quitting while EnumFontFamiliesEx runs and conses the
+         list it will return.  That's because get_frame_dc acquires
+         the critical section, so we cannot quit before we release it
+         in release_frame_dc.  */
+      Vinhibit_quit = Qt;
       dc = get_frame_dc (f);
 
       EnumFontFamiliesEx (dc, &match_data.pattern,
                           (FONTENUMPROC) add_font_entity_to_list,
                           (LPARAM) &match_data, 0);
       release_frame_dc (f, dc);
+      Vinhibit_quit = prev_quit;
     }
 
   return match_data.list;
@@ -844,12 +874,19 @@ w32font_match_internal (struct frame *f, Lisp_Object font_spec,
   if (opentype_only)
     match_data.pattern.lfOutPrecision = OUT_OUTLINE_PRECIS;
 
+  /* Prevent quitting while EnumFontFamiliesEx runs and conses the
+     list it will return.  That's because get_frame_dc acquires the
+     critical section, so we cannot quit before we release it in
+     release_frame_dc.  */
+  Lisp_Object prev_quit = Vinhibit_quit;
+  Vinhibit_quit = Qt;
   dc = get_frame_dc (f);
 
   EnumFontFamiliesEx (dc, &match_data.pattern,
                       (FONTENUMPROC) add_one_font_entity_to_list,
                       (LPARAM) &match_data, 0);
   release_frame_dc (f, dc);
+  Vinhibit_quit = prev_quit;
 
   return NILP (match_data.list) ? Qnil : XCAR (match_data.list);
 }
@@ -2064,6 +2101,12 @@ list_all_matching_fonts (struct font_callback_data *match_data)
   Lisp_Object families = w32font_list_family (XFRAME (match_data->frame));
   struct frame *f = XFRAME (match_data->frame);
 
+  /* Prevent quitting while EnumFontFamiliesEx runs and conses the
+     list it will return.  That's because get_frame_dc acquires the
+     critical section, so we cannot quit before we release it in
+     release_frame_dc.  */
+  Lisp_Object prev_quit = Vinhibit_quit;
+  Vinhibit_quit = Qt;
   dc = get_frame_dc (f);
 
   while (!NILP (families))
@@ -2091,6 +2134,7 @@ list_all_matching_fonts (struct font_callback_data *match_data)
     }
 
   release_frame_dc (f, dc);
+  Vinhibit_quit = prev_quit;
 }
 
 static Lisp_Object
diff --git a/src/w32uniscribe.c b/src/w32uniscribe.c
index 1584d80f203..e4055638cc4 100644
--- a/src/w32uniscribe.c
+++ b/src/w32uniscribe.c
@@ -89,12 +89,19 @@ uniscribe_list_family (struct frame *f)
   /* Limit enumerated fonts to outline fonts to save time.  */
   font_match_pattern.lfOutPrecision = OUT_OUTLINE_PRECIS;
 
+  /* Prevent quitting while EnumFontFamiliesEx runs and conses the
+     list it will return.  That's because get_frame_dc acquires the
+     critical section, so we cannot quit before we release it in
+     release_frame_dc.  */
+  Lisp_Object prev_quit = Vinhibit_quit;
+  Vinhibit_quit = Qt;
   dc = get_frame_dc (f);
 
   EnumFontFamiliesEx (dc, &font_match_pattern,
                       (FONTENUMPROC) add_opentype_font_name_to_list,
                       (LPARAM) &list, 0);
   release_frame_dc (f, dc);
+  Vinhibit_quit = prev_quit;
 
   return list;
 }