Zero out uninitialized memory so as not to write stack garbage to dump file

Also check return from XFetchName()

Signed-off-by: Jim Rees <rees@umich.edu>

2 files changed, 11 insertions, 8 deletions

diff --git a/multiVis.c b/multiVis.c
index 2d8e206..97f740e 100644
--- a/multiVis.c
+++ b/multiVis.c
@@ -34,11 +34,12 @@ from The Open Group.
 
     ------------------------------------------------------------------------ **/
 
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/X.h>
-#include <stdio.h>
 #include "list.h"
 #include "wsutils.h"
 #include "multiVis.h"
@@ -354,7 +355,7 @@ ReadRegionsInList(Display *disp, Visual *fakeVis, int depth, int format,
 {
     image_region_type *reg;
     int dst_x, dst_y;           /* where in pixmap to write (UL) */
-    int diff;
+    int datalen, diff;
 
     XImage *reg_image, *ximage;
     int srcRect_x, srcRect_y, srcRect_width, srcRect_height;
@@ -364,10 +365,11 @@ ReadRegionsInList(Display *disp, Visual *fakeVis, int depth, int format,
                           8, 0);
     bytes_per_line = ximage->bytes_per_line;
 
-    if (format == ZPixmap)
-        ximage->data = malloc(height * bytes_per_line);
-    else
-        ximage->data = malloc(height * bytes_per_line * depth);
+    datalen = height * bytes_per_line;
+    if (format != ZPixmap)
+        datalen *= depth;
+    ximage->data = malloc(datalen);
+    memset(ximage->data, 0, datalen);
 
     ximage->bits_per_pixel = depth; /** Valid only if format is ZPixmap ***/
 
diff --git a/xwd.c b/xwd.c
index c3c48e0..708a06e 100644
--- a/xwd.c
+++ b/xwd.c
@@ -241,6 +241,7 @@ Get24bitDirectColors(XColor **colors)
     for (i = 0; i < ncolors; i++) {
         tcol[i].pixel = i << 16 | i << 8 | i;
         tcol[i].red = tcol[i].green = tcol[i].blue = i << 8 | i;
+        tcol[i].flags = 0;
     }
 
     return ncolors;
@@ -336,8 +337,7 @@ Window_Dump(Window window, FILE *out)
     if (absy + height > dheight)
         height = dheight - absy;
 
-    XFetchName(dpy, window, &win_name);
-    if (!win_name || !win_name[0]) {
+    if (!XFetchName(dpy, window, &win_name) || !win_name || !win_name[0]) {
         win_name = default_win_name;
         got_win_name = False;
     }
@@ -430,6 +430,7 @@ Window_Dump(Window window, FILE *out)
      */
     if (debug)
         outl("xwd: Constructing and dumping file header.\n");
+    memset(&header, 0, SIZEOF(XWDheader));
     header.header_size = (CARD32) header_size;
     header.file_version = (CARD32) XWD_FILE_VERSION;
     header.pixmap_format = (CARD32) format;