+
+ /*
+ * Generic code to handle any other error.
+ *
+ * Slightly nasty hack here: we want to return a static string
+ * which the caller will never have to worry about freeing, but on
+ * the other hand if we call FormatMessage to get it then it will
+ * want to either allocate a buffer or write into one we own.
+ *
+ * So what we do is to maintain a tree234 of error strings we've
+ * already used. New ones are allocated from the heap, but then
+ * put in this tree and kept forever.
+ */
+
+ if (!errstrings)
+ errstrings = newtree234(errstring_compare);
+
+ es = find234(errstrings, &error, errstring_find);
+
+ if (!es) {
+ int bufsize, bufused;
+
+ es = snew(struct errstring);
+ es->error = error;
+ /* maximum size for FormatMessage is 64K */
+ bufsize = 65535 + sizeof(prefix);
+ es->text = snewn(bufsize, char);
+ strcpy(es->text, prefix);
+ bufused = strlen(es->text);
+ if (!FormatMessage((FORMAT_MESSAGE_FROM_SYSTEM |
+ FORMAT_MESSAGE_IGNORE_INSERTS), NULL, error,
+ MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+ es->text + bufused, bufsize - bufused, NULL)) {
+ sprintf(es->text + bufused,
+ "Windows error code %d (and FormatMessage returned %d)",
+ error, GetLastError());
+ } else {
+ int len = strlen(es->text);
+ if (len > 0 && es->text[len-1] == '\n')
+ es->text[len-1] = '\0';
+ }
+ es->text = sresize(es->text, strlen(es->text) + 1, char);
+ add234(errstrings, es);
+ }
+
+ return es->text;