Handle -Wdiscarded-qualifiers warnings for XawTextBlock ptr

xclipboard.c: In function ‘NewCurrentClip’:
xclipboard.c:384:29: warning: passing argument 1 of ‘NewCurrentClipContents’
 discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
  384 |     NewCurrentClipContents ("", 0);
      |                             ^~
xclipboard.c:77:44: note: expected ‘char *’ but argument is of type
 ‘const char *’
   77 | static void NewCurrentClipContents ( char *data, int len );
      |                                      ~~~~~~^~~~
xclipboard.c: In function ‘EraseTextWidget’:
xclipboard.c:420:15: warning: assignment discards ‘const’ qualifier from
 pointer target type [-Wdiscarded-qualifiers]
  420 |     block.ptr = "";
      |               ^

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/app/xclipboard/-/merge_requests/4>

1 files changed, 4 insertions, 2 deletions

diff --git a/xclipboard.c b/xclipboard.c
index 50d8741..d331c52 100644
--- a/xclipboard.c
+++ b/xclipboard.c
@@ -377,11 +377,13 @@ WMProtocols(Widget w, XEvent *ev, String *params, Cardinal *n)
     }
 }
 
+static char empty_string[] = "";
+
 /* ARGUSED */
 static void
 NewCurrentClip(Widget w, XEvent *ev, String *parms, Cardinal *np)
 {
-    NewCurrentClipContents ("", 0);
+    NewCurrentClipContents (empty_string, 0);
 }
 
 static void
@@ -417,7 +419,7 @@ EraseTextWidget(void)
 {
     XawTextBlock block;
 
-    block.ptr = "";
+    block.ptr = empty_string;
     block.length = 0;
     block.firstPos = 0;
     block.format = FMT8BIT;