Merge commit 'f5d46d332258dcd8ca623019ece1d5e5bb74142b'

* commit 'f5d46d332258dcd8ca623019ece1d5e5bb74142b':
  vmnc: check that subrectangles fit into their containing rectangles

See 6ba02602aa7fc7d38db582e75b8b093fb3c1608d

This merge keeps our condition against w-i and h-j instead of bw and bh.
One may be more correct than the other, but I'm keeping our behaviour
here for safety reasons.

The style and formatting is merged.

Merged-by: Clément Bœsch <u@pkh.me>

diff --cc libavcodec/vmnc.c
index 49abb776f2d2cc6675a2884c8940908f4d2ba7cb,7a01f1e2e63b88a48b3c636367c23b4286a6f0bb..a756dab2111e51f6fb59d9e5124ddeec478f687a
--- 1/libavcodec/vmnc.c
--- 2/libavcodec/vmnc.c
+++ b/libavcodec/vmnc.c
@@@ -291,13 -292,19 +292,19 @@@ static int decode_hextile(VmncContext *
                          fg = vmnc_get_pixel(gb, bpp, c->bigendian);
                      xy = bytestream2_get_byte(gb);
                      wh = bytestream2_get_byte(gb);
-                     if (   (xy >> 4) + (wh >> 4) + 1 > w - i
-                         || (xy & 0xF) + (wh & 0xF)+1 > h - j) {
+ 
+                     rect_x = xy >> 4;
+                     rect_y = xy & 0xF;
+                     rect_w = (wh >> 4) + 1;
+                     rect_h = (wh & 0xF) + 1;
+ 
 -                    if (rect_x + rect_w > bw || rect_y + rect_h > bh) {
 -                        av_log(c->avctx, AV_LOG_ERROR, "Invalid subrect\n");
++                    if (rect_x + rect_w > w - i || rect_y + rect_h > h - j) {
 +                        av_log(c->avctx, AV_LOG_ERROR, "Rectangle outside picture\n");
                          return AVERROR_INVALIDDATA;
                      }
-                     paint_rect(dst2, xy >> 4, xy & 0xF,
-                                (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
+ 
+                     paint_rect(dst2, rect_x, rect_y,
+                                rect_w, rect_h, fg, bpp, stride);
                  }
              }
          }