+
+ if (read_context != 1 ||
+ ((cp = context_find ("Welcome")) && strcasecmp (cp, "disable") == 0)) {
+ allow_version_check = 0;
+ } else if ((cp = getenv ("MHCONTEXT")) != NULL && *cp != '\0') {
+ /* Context file comes from $MHCONTEXT, so only print the message
+ if the context file has an older version. If it does, or if it
+ doesn't have a version at all, update the version. */
+ check_older_version = 1;
+ }
+
+ /* Check to see if the user is running a different (or older, if
+ specified) version of nmh than they had run before, and notify them
+ if so. But only if read_context was set to a value to enable. */
+ if (allow_version_check && isatty (fileno (stdin)) &&
+ isatty (fileno (stdout)) && isatty (fileno (stderr))) {
+ if (nmh_version_changed (check_older_version)) {
+ printf ("==================================================="
+ "=====================\n");
+ printf ("Welcome to nmh version %s\n\n", VERSION);
+ printf ("See the release notes in %s/NEWS\n\n",
+ mhdocdir);
+ print_intro (stdout, 1);
+ printf ("\nThis message will not be repeated until "
+ "nmh is next updated.\n");
+ printf ("==================================================="
+ "=====================\n\n");
+
+ fputs ("Press enter to continue: ", stdout);
+ (void) read_line ();
+ putchar ('\n');
+ }
+ }
+ } else {
+ if ((status = context_foil(NULL)) != OK) {
+ advise("", "failed to create minimal profile/context");
+ }
+ }
+
+ /* Allow the user to set a locale in their profile. Otherwise, use the
+ "" string to pull it from their environment, see setlocale(3). */
+ if ((locale = context_find ("locale")) == NULL) {
+ locale = "";
+ }
+
+ if (! setlocale (LC_ALL, locale)) {
+ inform("setlocale failed, check your LC_ALL, LC_CTYPE, and LANG "
+ "environment variables, continuing...");
+ }
+
+ return status;
+}
+
+
+/*
+ * Check stored version, and return 1 if out-of-date or non-existent.
+ * Because the output of "mhparam version" is prefixed with "nmh-",
+ * use that prefix here.
+ */
+int
+nmh_version_changed (int older) {
+ const char *const context_version = context_find("Version");
+
+ if (older) {
+ /* Convert the version strings to floats and compare them. This will
+ break for versions with multiple decimal points, etc. */
+ const float current_version = strtof (VERSION, NULL);
+ const float old_version =
+ context_version && has_prefix(context_version, "nmh-")
+ ? strtof (context_version + 4, NULL)
+ : 99999999;
+
+ if (context_version == NULL || old_version < current_version) {
+ context_replace ("Version", "nmh-" VERSION);
+ }
+
+ return old_version < current_version;
+ }
+
+ if (context_version == NULL || strcmp(context_version, "nmh-" VERSION) != 0) {
+ context_replace ("Version", "nmh-" VERSION);
+ return 1;
+ }
+
+ return 0;
+}
+
+
+/* contains8bit returns true if any byte from start onwards fails
+ * isascii(3), i.e. is outside [0, 0x7f]. If start is NULL it returns
+ * false. Bytes are examined until a NUL byte, or, if end is not NULL,
+ * whilst start is before end. */
+bool contains8bit(const char *start, const char *end)
+{
+ const char *p;
+ char c;
+
+ if (!start)
+ return false;
+
+ p = start;
+ if (end) {
+ while (p < end && (c = (*p++)))
+ if (!isascii((unsigned char)c))
+ return true;