Turn an assert into a nice error message.

git-svn-id: svn://svn.tartarus.org/sgt/utils@8361 cda61777-01e9-0310-a592-d414129be87e

diff --git a/xcopy/xcopy.c b/xcopy/xcopy.c
index a06789a..140716a 100644 (file)
--- a/xcopy/xcopy.c
+++ b/xcopy/xcopy.c
@@ -448,23 +448,26 @@ void do_paste(Window window, Atom property, int Delete) {
                               Delete, AnyPropertyType, &actual_type,
                               &actual_format, &nitems, &bytes_after,
                               (unsigned char **) &data) == Success) {
-       /*
-        * We expect all returned chunks of data to be multiples of
-        * 4 bytes (because we can only request the subsequent
-        * starting offset in 4-byte increments). Of course you can
-        * store an odd number of bytes in a selection, so this
-        * can't be the case every time XGetWindowProperty returns;
-        * but it should be the case every time it returns _and
-        * there is more data to come_.
-        * 
-        * Hence, whenever XGetWindowProperty returns, we verify
-        * that the size of the data returned _last_ time was
-        * divisible by 4.
-        */
-       if (nitems > 0)
-           assert((nread & 3) == 0);
-
        if (nitems > 0) {
+           /*
+            * We expect all returned chunks of data to be
+            * multiples of 4 bytes (because we can only request
+            * the subsequent starting offset in 4-byte
+            * increments). Of course you can store an odd number
+            * of bytes in a selection, so this can't be the case
+            * every time XGetWindowProperty returns; but it
+            * should be the case every time it returns _and there
+            * is more data to come_.
+            *
+            * Hence, whenever XGetWindowProperty returns, we
+            * verify that the size of the data returned _last_
+            * time was divisible by 4.
+            */
+           if ((nread & 3) != 0) {
+               error("unexpected data size: %d read (not a multiple"
+                     " of 4), but more to come\n", nread);
+           }
+
            if (expected_type != (Atom)None && actual_type != expected_type) {
                char *expout = XGetAtomName(disp, expected_type);
                char *gotout = (actual_type == (Atom)None ? "None" :