Resolve clang's conditional-uninitialize warnings

src/hb-ot-layout-gpos-table.hh

@@ -262,7 +262,7 @@ struct AnchorFormat2
     hb_font_t *font = c->font;
     unsigned int x_ppem = font->x_ppem;
     unsigned int y_ppem = font->y_ppem;
-    hb_position_t cx, cy;
+    hb_position_t cx = 0, cy = 0;
     hb_bool_t ret;
 
     ret = (x_ppem || y_ppem) &&

src/hb-ot-shape-normalize.cc

@@ -119,7 +119,7 @@ skip_char (hb_buffer_t *buffer)
 static inline unsigned int
 decompose (const hb_ot_shape_normalize_context_t *c, bool shortest, hb_codepoint_t ab)
 {
-  hb_codepoint_t a, b, a_glyph, b_glyph;
+  hb_codepoint_t a = 0, b = 0, a_glyph = 0, b_glyph = 0;
   hb_buffer_t * const buffer = c->buffer;
   hb_font_t * const font = c->font;
 
@@ -164,7 +164,7 @@ decompose_current_character (const hb_ot_shape_normalize_context_t *c, bool shor
 {
   hb_buffer_t * const buffer = c->buffer;
   hb_codepoint_t u = buffer->cur().codepoint;
-  hb_codepoint_t glyph;
+  hb_codepoint_t glyph = 0;
 
   if (shortest && c->font->get_nominal_glyph (u, &glyph))
   {

util/view-cairo.cc

@@ -49,7 +49,7 @@ view_cairo_t::render (const font_options_t *font_opts)
   double leading = font_height + view_options.line_space;
 
   /* Calculate surface size. */
-  double w, h;
+  double w = 0, h = 0;
   (vertical ? w : h) = (int) lines->len * leading - view_options.line_space;
   (vertical ? h : w) = 0;
   for (unsigned int i = 0; i < lines->len; i++) {