Avoid compilation warnings with GCC 7 on MS-Windows

* src/w32term.c (w32_setup_relief_color, construct_mouse_click)
(w32_read_socket): Initialize variables to shut up bogus
compilation warnings from GCC 7.
* src/unexw32.c (COPY_CHUNK, COPY_PROC_CHUNK): Cast to DWORD_PTR
to avoid compiler warnings about printing signed values using %x
format spec.
* src/dispnew.c (adjust_glyph_matrix): Add eassert to avoid
compiler warning about possible NULL pointer dereference.
* src/lisp.h (pI): Tweak the definition some more for MinGW64.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/w32term.c b/src/w32term.c
index e62ae7e8426..a7a510b9ecb 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -1645,6 +1645,7 @@ w32_setup_relief_color (struct frame *f, struct relief *relief, double factor,
   if (w32_alloc_lighter_color (f, &pixel, factor, delta))
     xgcv.foreground = relief->pixel = pixel;
 
+  xgcv.font = NULL;     /* avoid compiler warnings */
   if (relief->gc == 0)
     {
 #if 0 /* TODO: stipple */
@@ -3087,8 +3088,8 @@ parse_button (int message, int xbutton, int * pbutton, int * pup)
 static Lisp_Object
 construct_mouse_click (struct input_event *result, W32Msg *msg, struct frame *f)
 {
-  int button;
-  int up;
+  int button = 0;
+  int up = 0;
 
   parse_button (msg->msg.message, HIWORD (msg->msg.wParam),
                 &button, &up);
@@ -4976,8 +4977,8 @@ w32_read_socket (struct terminal *terminal,
             /* If we decide we want to generate an event to be seen
                by the rest of Emacs, we put it here.  */
             bool tool_bar_p = 0;
-            int button;
-            int up;
+            int button = 0;
+            int up = 0;
 
             f = (x_mouse_grabbed (dpyinfo) ? dpyinfo->last_mouse_frame
                  : x_window_to_frame (dpyinfo, msg.msg.hwnd));