michael@0: From: Robert O'Callahan <robert@ocallahan.org>
michael@0: Bug 717178. Part 1: Don't crash when passing a nil scaled-font to _name_tables_match. r=jfkthame
michael@0: 
michael@0: diff --git a/gfx/cairo/cairo/src/cairo-dwrite-font.cpp b/gfx/cairo/cairo/src/cairo-dwrite-font.cpp
michael@0: --- a/gfx/cairo/cairo/src/cairo-dwrite-font.cpp
michael@0: +++ b/gfx/cairo/cairo/src/cairo-dwrite-font.cpp
michael@0: @@ -1489,17 +1489,18 @@ static cairo_bool_t
michael@0:      unsigned long size1;
michael@0:      unsigned long size2;
michael@0:      cairo_int_status_t status1;
michael@0:      cairo_int_status_t status2;
michael@0:      unsigned char *buffer1;
michael@0:      unsigned char *buffer2;
michael@0:      cairo_bool_t result = false;
michael@0:  
michael@0: -    if (!font1->backend->load_truetype_table ||
michael@0: +    if (!font1->backend || !font2->backend ||
michael@0: +        !font1->backend->load_truetype_table ||
michael@0:          !font2->backend->load_truetype_table)
michael@0:          return false;
michael@0:  
michael@0:      status1 = font1->backend->load_truetype_table (font1,
michael@0:                                                     TT_TAG_name, 0, NULL, &size1);
michael@0:      status2 = font2->backend->load_truetype_table (font2,
michael@0:                                                     TT_TAG_name, 0, NULL, &size2);
michael@0:      if (status1 || status2)