Various error-handling fixes, mostly in Unix PuTTY but one (failure

to save a session) crosses over into the platform-independent side.

[originally from svn r3041]

unix/gtkdlg.c

@@ -2337,6 +2337,13 @@ void old_keyfile_warning(void)
      */
 }
 
+void fatal_message_box(void *window, char *msg)
+{
+    messagebox(window, "PuTTY Fatal Error", msg,
+               string_width("REASONABLY LONG LINE OF TEXT FOR BASIC SANITY"),
+               "OK", 'o', 1, 1, NULL);
+}
+
 void fatalbox(char *p, ...)
 {
     va_list ap;
@@ -2344,23 +2351,7 @@ void fatalbox(char *p, ...)
     va_start(ap, p);
     msg = dupvprintf(p, ap);
     va_end(ap);
-    messagebox(NULL, "PuTTY Fatal Error", msg,
-               string_width("REASONABLY LONG LINE OF TEXT FOR BASIC SANITY"),
-               "OK", 'o', 1, 1, NULL);
-    sfree(msg);
-    cleanup_exit(1);
-}
-void connection_fatal(void *frontend, char *p, ...)
-{
-    va_list ap;
-    char *msg;
-    va_start(ap, p);
-    msg = dupvprintf(p, ap);
-    va_end(ap);
-    messagebox(GTK_WIDGET(get_window(frontend)),
-               "PuTTY Fatal Error", msg,
-               string_width("REASONABLY LONG LINE OF TEXT FOR BASIC SANITY"),
-               "OK", 'o', 1, 1, NULL);
+    fatal_message_box(NULL, msg);
     sfree(msg);
     cleanup_exit(1);
 }

unix/pterm.c

@@ -86,6 +86,23 @@ char *x_get_default(const char *key)
     return XGetDefault(GDK_DISPLAY(), app_name, key);
 }
 
+void connection_fatal(void *frontend, char *p, ...)
+{
+    Terminal *term = (Terminal *)frontend;
+    struct gui_data *inst = (struct gui_data *)term->frontend;
+
+    va_list ap;
+    char *msg;
+    va_start(ap, p);
+    msg = dupvprintf(p, ap);
+    va_end(ap);
+    inst->exited = TRUE;
+    fatal_message_box(inst->window, msg);
+    sfree(msg);
+    if (inst->cfg.close_on_exit == FORCE_ON)
+        cleanup_exit(1);
+}
+
 /*
  * Default settings that are specific to pterm.
  */
@@ -1018,7 +1035,8 @@ gint timer_func(gpointer data)
     struct gui_data *inst = (struct gui_data *)data;
     int exitcode;
 
-    if ((exitcode = inst->back->exitcode(inst->backhandle)) >= 0) {
+    if (!inst->exited &&
+        (exitcode = inst->back->exitcode(inst->backhandle)) >= 0) {
 	inst->exited = TRUE;
 	if (inst->cfg.close_on_exit == FORCE_ON ||
 	    (inst->cfg.close_on_exit == AUTO && exitcode == 0))
@@ -1032,10 +1050,17 @@ gint timer_func(gpointer data)
 
 void fd_input_func(gpointer data, gint sourcefd, GdkInputCondition condition)
 {
-    select_result(sourcefd,
-		  (condition == GDK_INPUT_READ ? 1 :
-		   condition == GDK_INPUT_WRITE ? 2 :
-		   condition == GDK_INPUT_EXCEPTION ? 4 : -1));
+    /*
+     * We must process exceptional notifications before ordinary
+     * readability ones, or we may go straight past the urgent
+     * marker.
+     */
+    if (condition & GDK_INPUT_EXCEPTION)
+        select_result(sourcefd, 4);
+    if (condition & GDK_INPUT_READ)
+        select_result(sourcefd, 1);
+    if (condition & GDK_INPUT_WRITE)
+        select_result(sourcefd, 2);
 }
 
 void destroy(GtkWidget *widget, gpointer data)
@@ -2437,13 +2462,24 @@ int pt_main(int argc, char **argv)
 
     uxsel_init();
 
+    term_size(inst->term, inst->cfg.height, inst->cfg.width, inst->cfg.savelines);
+
     inst->back = select_backend(&inst->cfg);
     {
-	char *realhost;
+	char *realhost, *error;
 
-	inst->back->init((void *)inst->term, &inst->backhandle, &inst->cfg,
-			 inst->cfg.host, inst->cfg.port, &realhost,
-			 inst->cfg.tcp_nodelay);
+	error = inst->back->init((void *)inst->term, &inst->backhandle,
+                                 &inst->cfg, inst->cfg.host, inst->cfg.port,
+                                 &realhost, inst->cfg.tcp_nodelay);
+
+	if (error) {
+	    char *msg = dupprintf("Unable to open connection to %s:\n%s",
+                                  inst->cfg.host, error);
+            inst->exited = TRUE;
+	    fatal_message_box(inst->window, msg);
+            sfree(msg);
+	    return 0;
+	}
 
         if (inst->cfg.wintitle[0])
             set_title(inst, inst->cfg.wintitle);
@@ -2457,8 +2493,6 @@ int pt_main(int argc, char **argv)
 
     term_provide_resize_fn(inst->term, inst->back->size, inst->backhandle);
 
-    term_size(inst->term, inst->cfg.height, inst->cfg.width, inst->cfg.savelines);
-
     inst->ldisc =
 	ldisc_create(&inst->cfg, inst->term, inst->back, inst->backhandle, inst);
     ldisc_send(inst->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */

unix/ptermm.c

@@ -3,6 +3,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "putty.h"
 
@@ -16,6 +17,16 @@ int cfgbox(Config *cfg)
     return 1;			       /* no-op in pterm */
 }
 
+void fatal_message_box(void *window, char *msg)
+{
+    /* also a no-op in pterm */
+}
+
+void cleanup_exit(int code)
+{
+    exit(code);
+}
+
 int process_nonoption_arg(char *arg, Config *cfg)
 {
     return 0;                          /* pterm doesn't have any. */

unix/unix.h

@@ -58,6 +58,9 @@ long get_windowid(void *frontend);
 /* Things gtkdlg.c needs from pterm.c */
 void *get_window(void *frontend);      /* void * to avoid depending on gtk.h */
 
+/* Things pterm.c needs from gtkdlg.c */
+void fatal_message_box(void *window, char *msg);
+
 /* Things pterm.c needs from {ptermm,uxputty}.c */
 char *make_default_wintitle(char *hostname);
 int process_nonoption_arg(char *arg, Config *cfg);

unix/uxstore.c

@@ -5,7 +5,9 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <assert.h>
+#include <errno.h>
 #include <ctype.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -132,24 +134,32 @@ static char *fgetline(FILE *fp)
  * file somewhere or other.
  */
 
-void *open_settings_w(const char *sessionname)
+void *open_settings_w(const char *sessionname, char **errmsg)
 {
     char filename[FILENAME_MAX];
     FILE *fp;
 
+    *errmsg = NULL;
+
     /*
-     * Start by making sure the sessions subdir exists. Ignore the
-     * error return from mkdir since it's perfectly likely to be
-     * `already exists', and any other error will trip us up later
-     * on so there's no real need to catch it now.
+     * Start by making sure the .putty directory and its sessions
+     * subdir actually exist. Ignore error returns from mkdir since
+     * they're perfectly likely to be `already exists', and any
+     * other error will trip us up later on so there's no real need
+     * to catch it now.
      */
+    make_filename(filename, INDEX_DIR, sessionname);
+    mkdir(filename, 0700);
     make_filename(filename, INDEX_SESSIONDIR, sessionname);
     mkdir(filename, 0700);
 
     make_filename(filename, INDEX_SESSION, sessionname);
     fp = fopen(filename, "w");
-    if (!fp)
-	return NULL;		       /* can't open */
+    if (!fp) {
+        *errmsg = dupprintf("Unable to create %s: %s",
+                            filename, strerror(errno));
+	return NULL;                   /* can't open */
+    }
     return fp;
 }