Save backup config during /upgrade

If the user has modified their config within Irssi since the config was
last saved and then runs /upgrade, then we want to save a backup config
(in ~/.irssi/config.clientbackup), which is reloaded upon the upgrade
being done.

src/common.h

@@ -5,6 +5,7 @@
 
 #define IRSSI_GLOBAL_CONFIG "irssi.conf" /* config file name in /etc/ */
 #define IRSSI_HOME_CONFIG "config" /* config file name in ~/.irssi/ */
+#define IRSSI_HOME_CONFIG_BACKUP "config.clientbackup" /* config file name for upgrades */
 
 #define IRSSI_ABI_VERSION 10
 
@@ -68,6 +69,7 @@ int g_input_add_full(GIOChannel *source, int priority, int condition,
 const char *get_irssi_dir(void);
 /* return full path for ~/.irssi/config */
 const char *get_irssi_config(void);
+void set_irssi_config(char *);
 
 /* max. size for %d */
 #define MAX_INT_STRLEN ((sizeof(int) * CHAR_BIT + 2) / 3 + 1)

src/core/core.c

@@ -76,6 +76,11 @@ const char *get_irssi_config(void)
         return irssi_config_file;
 }
 
+void set_irssi_config(char *path)
+{
+	irssi_config_file = path;
+}
+
 static void sig_reload_config(int signo)
 {
         reload_config = TRUE;

src/core/session.c

@@ -26,6 +26,7 @@
 #include "net-sendbuffer.h"
 #include "pidwait.h"
 #include "lib-config/iconfig.h"
+#include "settings.h"
 
 #include "chat-protocols.h"
 #include "servers.h"
@@ -58,8 +59,8 @@ void session_upgrade(void)
 /* SYNTAX: UPGRADE [<irssi binary path>] */
 static void cmd_upgrade(const char *data)
 {
-	CONFIG_REC *session;
-	char *session_file, *str;
+	CONFIG_REC *session, *config;
+	char *session_file, *config_file, *str;
 	char *binary;
 
 	if (*data == '\0')
@@ -77,12 +78,19 @@ static void cmd_upgrade(const char *data)
         config_write(session, NULL, -1);
         config_close(session);
 
+	/* save the config */
+	config_file = g_strdup_printf("%s/"IRSSI_HOME_CONFIG_BACKUP, get_irssi_dir());
+	unlink(config_file);
+
+	signal_emit("command save", 1, config_file);
+
 	/* data may contain some other program as well, like
 	   /UPGRADE /usr/bin/screen irssi */
 	str = g_strdup_printf("%s --noconnect --session=%s --home=%s --config=%s",
-			      binary, session_file, get_irssi_dir(), get_irssi_config());
+			      binary, session_file, get_irssi_dir(), config_file);
 	g_free(binary);
 	g_free(session_file);
+	g_free(config_file);
         session_args = g_strsplit(str, " ", -1);
         g_free(str);
 
@@ -315,20 +323,42 @@ static void sig_session_restore(CONFIG_REC *config)
 
 static void sig_init_finished(void)
 {
-	CONFIG_REC *session;
-
-	if (session_file == NULL)
-		return;
+	CONFIG_REC *session, *config;
+	char *config_file;
+	FILE *fp;
 
+	if (session_file != NULL) {
 		session = config_open(session_file, -1);
-	if (session == NULL)
-		return;
-
+		if (session != NULL) {
 			config_parse(session);
 			signal_emit("session restore", 1, session);
 			config_close(session);
+		}
 
 		unlink(session_file);
+	}
+
+	config_file = g_strdup_printf("%s/"IRSSI_HOME_CONFIG_BACKUP, get_irssi_dir());
+
+	if ((fp = fopen(config_file, "r")) != NULL) {
+		/* load backup */
+		signal_emit("command reload", 1, config_file);
+		backupconfig = parse_configfile(config_file);
+
+		/* set irssi_config_file back to default so any future saves/reloads behave as expected */
+		set_irssi_config(g_strdup_printf("%s/"IRSSI_HOME_CONFIG, get_irssi_dir()));
+		/* load regular config into mainconfig */
+		signal_emit("command reload", 1, get_irssi_config());
+
+		/* setup mainconfig so that data from backup config is saved on next save */
+		mainconfig->mainnode = backupconfig->mainnode;
+		mainconfig->cache = backupconfig->cache;
+		mainconfig->cache_nodes = backupconfig->cache_nodes;
+
+		fclose(fp);
+	}
+
+	g_free(config_file);
 }
 
 void session_register_options(void)

src/core/settings.c

@@ -34,6 +34,7 @@
 #define SETTINGS_AUTOSAVE_TIMEOUT (1000*60*60) /* 1 hour */
 
 CONFIG_REC *mainconfig;
+CONFIG_REC *backupconfig = NULL;
 
 static GString *last_errors;
 static GSList *last_invalid_modules;
@@ -673,7 +674,7 @@ static unsigned int file_checksum(const char *fname)
 	return checksum;
 }
 
-static void irssi_config_save_state(const char *fname)
+void irssi_config_save_state(const char *fname)
 {
 	struct stat statbuf;
 
@@ -703,7 +704,7 @@ int irssi_config_is_changed(const char *fname)
 		 config_last_checksum != file_checksum(fname));
 }
 
-static CONFIG_REC *parse_configfile(const char *fname)
+CONFIG_REC *parse_configfile(const char *fname)
 {
 	CONFIG_REC *config;
 	struct stat statbuf;
@@ -827,6 +828,9 @@ int settings_save(const char *fname, int autosave)
 		g_free(str);
 	}
 	signal_emit("setup saved", 2, fname, GINT_TO_POINTER(autosave));
+	if (backupconfig != NULL && backupconfig->fname != NULL) {
+		unlink(backupconfig->fname);
+	}
         return !error;
 }
 

src/core/settings.h

@@ -51,6 +51,7 @@ typedef struct {
 #define iconfig_node_add_list(a, b) config_node_add_list(mainconfig, a, b)
 
 extern struct _CONFIG_REC *mainconfig;
+extern struct _CONFIG_REC *backupconfig;
 extern const char *default_config;
 
 /* Functions for handling the "settings" node of Irssi configuration */
@@ -123,7 +124,9 @@ void settings_clean_invalid(void);
 /* if `fname' is NULL, the default is used */
 int settings_reread(const char *fname);
 int settings_save(const char *fname, int autosave);
+void  irssi_config_save_state(const char *fname);
 int irssi_config_is_changed(const char *fname);
+struct _CONFIG_REC *parse_configfile(const char *fname);
 
 void settings_init(void);
 void settings_deinit(void);

src/fe-common/core/fe-settings.c

@@ -364,9 +364,12 @@ static void cmd_save(const char *data)
 	if (*fname == '\0')
 		fname = mainconfig->fname;
 
-	if (!irssi_config_is_changed(fname))
-		settings_save_fe(fname);
-	else {
+	if (irssi_config_is_changed(fname) && backupconfig != NULL) {
+		/* config file modified outside irssi and backup config exists */
+		/* must not save and direct user to merge files outside of irssi */
+		printformat(NULL,NULL, MSGLEVEL_CLIENTNOTICE,
+			    TXT_CONFIG_CONFLICT, fname, backupconfig->fname);
+	} else if (irssi_config_is_changed(fname)) {
                 /* config file modified outside irssi */
 		printformat(NULL, NULL, MSGLEVEL_CLIENTNOTICE,
 			    TXT_CONFIG_MODIFIED, fname);
@@ -376,6 +379,8 @@ static void cmd_save(const char *data)
 		keyboard_entry_redirect((SIGNAL_FUNC) settings_save_confirm,
 					format, 0, g_strdup(fname));
 		g_free(format);
+	} else {
+		settings_save_fe(fname);
 	}
 
 	cmd_params_free(free_arg);

src/fe-common/core/module-formats.c

@@ -279,6 +279,7 @@ FORMAT_REC fecommon_core_formats[] = {
 	{ "config_saved", "Saved configuration to file $0", 1, { 0 } },
 	{ "config_reloaded", "Reloaded configuration", 1, { 0 } },
 	{ "config_modified", "Configuration file was modified since irssi was last started - do you want to overwrite the possible changes?", 1, { 0 } },
+	{ "config_conflict", "Configuration file was modified since irssi was last started and backup config from upgrade exists - please use external merge tool to merge $0 and $1 into $0. Config was not saved.", 2, { 0, 0 } },
 	{ "glib_error", "{error $0} $1", 2, { 0, 0 } },
 	{ "overwrite_config", "Overwrite config (y/N)?", 0 },
 	{ "set_title", "[{hilight $0}]", 1, { 0 } },

src/fe-common/core/module-formats.h

@@ -244,6 +244,7 @@ enum {
 	TXT_CONFIG_SAVED,
 	TXT_CONFIG_RELOADED,
 	TXT_CONFIG_MODIFIED,
+	TXT_CONFIG_CONFLICT,
 	TXT_GLIB_ERROR,
 	TXT_OVERWRITE_CONFIG,
 	TXT_SET_TITLE,