Constify strings in pref.h

Make all char * pointers in pref.h const to make it clear that these
strings are not mutable. This meant adding a number of (void *) casts
in calls to free(). Apart from being the right thing to do, this commit
makes the code more consistent, as many of the strings in pref.h were
already const.

While touching core/qthelper.cpp turn three instances of (void*) into
(void *).

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

6 files changed, 59 insertions, 58 deletions

diff --git a/core/cloudstorage.cpp b/core/cloudstorage.cpp
index 5a1f2b06a..11743303c 100644
--- a/core/cloudstorage.cpp
+++ b/core/cloudstorage.cpp
@@ -64,7 +64,7 @@ void CloudStorageAuthenticate::uploadFinished()
 		csSettings.setVerificationStatus(CS_NEED_TO_VERIFY);
 		report_error(qPrintable(tr("Cloud account verification required, enter PIN in preferences")));
 	} else if (cloudAuthReply == QLatin1String("[PASSWDCHANGED]")) {
-		free(prefs.cloud_storage_password);
+		free((void *)prefs.cloud_storage_password);
 		prefs.cloud_storage_password = prefs.cloud_storage_newpassword;
 		prefs.cloud_storage_newpassword = NULL;
 		emit passwordChangeSuccessful();
diff --git a/core/dive.c b/core/dive.c
index c85b869a3..07d47de6f 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -3623,11 +3623,12 @@ timestamp_t get_times()
 
 void set_userid(char *rUserId)
 {
+	char *userid = strdup(rUserId);
+	if (strlen(userid) > 30)
+		userid[30] = '\0';
 	if (prefs.userid)
-		free(prefs.userid);
-	prefs.userid = strdup(rUserId);
-	if (strlen(prefs.userid) > 30)
-		prefs.userid[30]='\0';
+		free((void *)prefs.userid);
+	prefs.userid = userid;
 }
 
 /* this sets a usually unused copy of the preferences with the units
diff --git a/core/pref.h b/core/pref.h
index d00d766a5..2cddf9220 100644
--- a/core/pref.h
+++ b/core/pref.h
@@ -22,9 +22,9 @@ typedef struct
 } partial_pressure_graphs_t;
 
 typedef struct {
-	char *access_token;
-	char *user_id;
-	char *album_id;
+	const char *access_token;
+	const char *user_id;
+	const char *album_id;
 } facebook_prefs_t;
 
 typedef struct {
@@ -46,15 +46,15 @@ enum deco_mode {
 typedef struct {
 	bool dont_check_for_updates;
 	bool dont_check_exists;
-	char *last_version_used;
-	char *next_check;
+	const char *last_version_used;
+	const char *next_check;
 } update_manager_prefs_t;
 
 typedef struct {
-	char *vendor;
-	char *product;
-	char *device;
-	char *device_name;
+	const char *vendor;
+	const char *product;
+	const char *device;
+	const char *device_name;
 	int download_mode;
 } dive_computer_prefs_t;
 
@@ -99,7 +99,7 @@ struct preferences {
 	short rulergraph;
 	short tankbar;
 	short save_userid_local;
-	char *userid;
+	const char *userid;
 	int ascrate75; // All rates in mm / sec
 	int ascrate50;
 	int ascratestops;
@@ -112,11 +112,11 @@ struct preferences {
 	enum deco_mode display_deco_mode;
 	depth_t bestmixend;
 	int proxy_type;
-	char *proxy_host;
+	const char *proxy_host;
 	int proxy_port;
 	short proxy_auth;
-	char *proxy_user;
-	char *proxy_pass;
+	const char *proxy_user;
+	const char *proxy_pass;
 	bool doo2breaks;
 	bool drop_stone_mode;
 	bool last_stop;   // At 6m?
@@ -138,10 +138,10 @@ struct preferences {
 	bool use_default_file;
 	short default_file_behavior;
 	facebook_prefs_t facebook;
-	char *cloud_storage_password;
-	char *cloud_storage_newpassword;
-	char *cloud_storage_email;
-	char *cloud_storage_email_encoded;
+	const char *cloud_storage_password;
+	const char *cloud_storage_newpassword;
+	const char *cloud_storage_email;
+	const char *cloud_storage_email_encoded;
 	bool save_password_local;
 	short cloud_verification_status;
 	bool cloud_background_sync;
diff --git a/core/qthelper.cpp b/core/qthelper.cpp
index 628fffa97..53cf1f841 100644
--- a/core/qthelper.cpp
+++ b/core/qthelper.cpp
@@ -537,11 +537,11 @@ QString uiLanguage(QLocale *callerLoc)
 		// messes things up there
 		dateFormat.replace("'en' 'den' d:'e'", " d");
 		if (!prefs.date_format_override || same_string(prefs.date_format, "")) {
-			free((void*)prefs.date_format);
+			free((void *)prefs.date_format);
 			prefs.date_format = strdup(qPrintable(dateFormat));
 		}
 		if (!prefs.date_format_override || same_string(prefs.date_format_short, "")) {
-			free((void*)prefs.date_format_short);
+			free((void *)prefs.date_format_short);
 			prefs.date_format_short = strdup(qPrintable(shortDateFormat));
 		}
 	}
@@ -549,7 +549,7 @@ QString uiLanguage(QLocale *callerLoc)
 		timeFormat = loc.timeFormat();
 		timeFormat.replace("(t)", "").replace(" t", "").replace("t", "").replace("hh", "h").replace("HH", "H").replace("'kl'.", "");
 		timeFormat.replace(".ss", "").replace(":ss", "").replace("ss", "");
-		free((void*)prefs.time_format);
+		free((void *)prefs.time_format);
 		prefs.time_format = strdup(qPrintable(timeFormat));
 	}
 	return uiLang;
@@ -1438,7 +1438,7 @@ int getCloudURL(QString &filename)
 	if (email.isEmpty() || same_string(prefs.cloud_storage_password, ""))
 		return report_error("Please configure Cloud storage email and password in the preferences");
 	if (email != prefs.cloud_storage_email_encoded) {
-		free(prefs.cloud_storage_email_encoded);
+		free((void *)prefs.cloud_storage_email_encoded);
 		prefs.cloud_storage_email_encoded = strdup(qPrintable(email));
 	}
 	filename = QString(QString(prefs.cloud_git_url) + "/%1[%1]").arg(email);
diff --git a/core/subsurface-qt/SettingsObjectWrapper.cpp b/core/subsurface-qt/SettingsObjectWrapper.cpp
index efd1cda6c..16f4471ed 100644
--- a/core/subsurface-qt/SettingsObjectWrapper.cpp
+++ b/core/subsurface-qt/SettingsObjectWrapper.cpp
@@ -47,7 +47,7 @@ void DiveComputerSettings::setVendor(const QString& vendor)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("dive_computer_vendor", vendor);
-	free(prefs.dive_computer.vendor);
+	free((void *)prefs.dive_computer.vendor);
 	prefs.dive_computer.vendor = copy_string(qPrintable(vendor));
 }
 
@@ -59,7 +59,7 @@ void DiveComputerSettings::setProduct(const QString& product)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("dive_computer_product", product);
-	free(prefs.dive_computer.product);
+	free((void *)prefs.dive_computer.product);
 	prefs.dive_computer.product = copy_string(qPrintable(product));
 }
 
@@ -71,7 +71,7 @@ void DiveComputerSettings::setDevice(const QString& device)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("dive_computer_device", device);
-	free(prefs.dive_computer.device);
+	free((void *)prefs.dive_computer.device);
 	prefs.dive_computer.device = copy_string(qPrintable(device));
 }
 
@@ -83,7 +83,7 @@ void DiveComputerSettings::setDeviceName(const QString& device_name)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("dive_computer_device_name", device_name);
-	free(prefs.dive_computer.device_name);
+	free((void *)prefs.dive_computer.device_name);
 	prefs.dive_computer.device_name = copy_string(qPrintable(device_name));
 }
 
@@ -144,7 +144,7 @@ void UpdateManagerSettings::setLastVersionUsed(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("LastVersionUsed", value);
-	free (prefs.update_manager.last_version_used);
+	free((void *)prefs.update_manager.last_version_used);
 	prefs.update_manager.last_version_used = copy_string(qPrintable(value));
 	emit lastVersionUsedChanged(value);
 }
@@ -157,7 +157,7 @@ void UpdateManagerSettings::setNextCheck(const QDate& date)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("NextCheck", date);
-	free (prefs.update_manager.next_check);
+	free((void *)prefs.update_manager.next_check);
 	prefs.update_manager.next_check = copy_string(qPrintable(date.toString("dd/MM/yyyy")));
 	emit nextCheckChanged(date);
 }
@@ -748,7 +748,7 @@ void FacebookSettings::setAccessToken (const QString& value)
 	s.beginGroup(subgroup);
 	s.setValue("ConnectToken", value);
 #endif
-	free(prefs.facebook.access_token);
+	free((void *)prefs.facebook.access_token);
 	prefs.facebook.access_token = copy_string(qPrintable(value));
 	emit accessTokenChanged(value);
 }
@@ -763,7 +763,7 @@ void FacebookSettings::setUserId(const QString& value)
 	s.beginGroup(subgroup);
 	s.setValue("UserId", value);
 #endif
-	free(prefs.facebook.user_id);
+	free((void *)prefs.facebook.user_id);
 	prefs.facebook.user_id = copy_string(qPrintable(value));
 	emit userIdChanged(value);
 }
@@ -778,7 +778,7 @@ void FacebookSettings::setAlbumId(const QString& value)
 	s.beginGroup(subgroup);
 	s.setValue("AlbumId", value);
 #endif
-	free(prefs.facebook.album_id);
+	free((void *)prefs.facebook.album_id);
 	prefs.facebook.album_id = copy_string(qPrintable(value));
 	emit albumIdChanged(value);
 }
@@ -891,7 +891,7 @@ void ProxySettings::setHost(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("proxy_host", value);
-	free(prefs.proxy_host);
+	free((void *)prefs.proxy_host);
 	prefs.proxy_host = copy_string(qPrintable(value));
 	emit hostChanged(value);
 }
@@ -925,7 +925,7 @@ void ProxySettings::setUser(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("proxy_user", value);
-	free(prefs.proxy_user);
+	free((void *)prefs.proxy_user);
 	prefs.proxy_user = copy_string(qPrintable(value));
 	emit userChanged(value);
 }
@@ -937,7 +937,7 @@ void ProxySettings::setPass(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("proxy_pass", value);
-	free(prefs.proxy_pass);
+	free((void *)prefs.proxy_pass);
 	prefs.proxy_pass = copy_string(qPrintable(value));
 	emit passChanged(value);
 }
@@ -1010,7 +1010,7 @@ void CloudStorageSettings::setPassword(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("password", value);
-	free(prefs.cloud_storage_password);
+	free((void *)prefs.cloud_storage_password);
 	prefs.cloud_storage_password = copy_string(qPrintable(value));
 	emit passwordChanged(value);
 }
@@ -1020,7 +1020,7 @@ void CloudStorageSettings::setNewPassword(const QString& value)
 	if (value == prefs.cloud_storage_newpassword)
 		return;
 	/*TODO: This looks like wrong, but 'new password' is not saved on disk, why it's on prefs? */
-	free(prefs.cloud_storage_newpassword);
+	free((void *)prefs.cloud_storage_newpassword);
 	prefs.cloud_storage_newpassword = copy_string(qPrintable(value));
 	emit newPasswordChanged(value);
 }
@@ -1032,7 +1032,7 @@ void CloudStorageSettings::setEmail(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("email", value);
-	free(prefs.cloud_storage_email);
+	free((void *)prefs.cloud_storage_email);
 	prefs.cloud_storage_email = copy_string(qPrintable(value));
 	emit emailChanged(value);
 }
@@ -1044,7 +1044,7 @@ void CloudStorageSettings::setUserId(const QString& value)
 	//WARNING: UserId is stored outside of any group, but it belongs to Cloud Storage.
 	QSettings s;
 	s.setValue("subsurface_webservice_uid", value);
-	free(prefs.userid);
+	free((void *)prefs.userid);
 	prefs.userid = copy_string(qPrintable(value));
 	emit userIdChanged(value);
 }
@@ -1054,7 +1054,7 @@ void CloudStorageSettings::setEmailEncoded(const QString& value)
 	if (value == prefs.cloud_storage_email_encoded)
 		return;
 	/*TODO: This looks like wrong, but 'email encoded' is not saved on disk, why it's on prefs? */
-	free(prefs.cloud_storage_email_encoded);
+	free((void *)prefs.cloud_storage_email_encoded);
 	prefs.cloud_storage_email_encoded = copy_string(qPrintable(value));
 	emit emailEncodedChanged(value);
 }
@@ -1113,8 +1113,8 @@ void CloudStorageSettings::setBaseUrl(const QString& value)
 
 	// dont free data segment.
 	if (prefs.cloud_base_url != default_prefs.cloud_base_url) {
-		free((void*)prefs.cloud_base_url);
-		free((void*)prefs.cloud_git_url);
+		free((void *)prefs.cloud_base_url);
+		free((void *)prefs.cloud_git_url);
 	}
 	QSettings s;
 	s.beginGroup(group);
@@ -1795,7 +1795,7 @@ void GeneralSettingsObjectWrapper::setDefaultFilename(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("default_filename", value);
-	free((void*)prefs.default_filename);
+	free((void *)prefs.default_filename);
 	prefs.default_filename = copy_string(qPrintable(value));
 	emit defaultFilenameChanged(value);
 }
@@ -1808,7 +1808,7 @@ void GeneralSettingsObjectWrapper::setDefaultCylinder(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("default_cylinder", value);
-	free((void*)prefs.default_cylinder);
+	free((void *)prefs.default_cylinder);
 	prefs.default_cylinder = copy_string(qPrintable(value));
 	emit defaultCylinderChanged(value);
 }
@@ -2012,7 +2012,7 @@ void  LanguageSettingsObjectWrapper::setLangLocale(const QString &value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("UiLangLocale", value);
-	free((void*)prefs.locale.lang_locale);
+	free((void *)prefs.locale.lang_locale);
 	prefs.locale.lang_locale = copy_string(qPrintable(value));
 	emit langLocaleChanged(value);
 }
@@ -2024,7 +2024,7 @@ void  LanguageSettingsObjectWrapper::setLanguage(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("UiLanguage", value);
-	free((void*)prefs.locale.language);
+	free((void *)prefs.locale.language);
 	prefs.locale.language = copy_string(qPrintable(value));
 	emit languageChanged(value);
 }
@@ -2036,7 +2036,7 @@ void  LanguageSettingsObjectWrapper::setTimeFormat(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("time_format", value);
-	free((void*)prefs.time_format);
+	free((void *)prefs.time_format);
 	prefs.time_format = copy_string(qPrintable(value));
 	emit timeFormatChanged(value);
 }
@@ -2049,7 +2049,7 @@ void  LanguageSettingsObjectWrapper::setDateFormat(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("date_format", value);
-	free((void*)prefs.date_format);
+	free((void *)prefs.date_format);
 	prefs.date_format = copy_string(qPrintable(value));
 	emit dateFormatChanged(value);
 }
@@ -2062,7 +2062,7 @@ void  LanguageSettingsObjectWrapper::setDateFormatShort(const QString& value)
 	QSettings s;
 	s.beginGroup(group);
 	s.setValue("date_format_short", value);
-	free((void*)prefs.date_format_short);
+	free((void *)prefs.date_format_short);
 	prefs.date_format_short = copy_string(qPrintable(value));
 	emit dateFormatShortChanged(value);
 }
diff --git a/mobile-widgets/qmlmanager.cpp b/mobile-widgets/qmlmanager.cpp
index b0e597f6f..2c28ccf83 100644
--- a/mobile-widgets/qmlmanager.cpp
+++ b/mobile-widgets/qmlmanager.cpp
@@ -383,7 +383,7 @@ void QMLManager::saveCloudCredentials()
 	s.setValue("cloud_verification_status", credentialStatus());
 	s.sync();
 	if (!same_string(prefs.cloud_storage_email, qPrintable(cloudUser))) {
-		free(prefs.cloud_storage_email);
+		free((void *)prefs.cloud_storage_email);
 		prefs.cloud_storage_email = strdup(qPrintable(cloudUser));
 		cloudCredentialsChanged = true;
 	}
@@ -396,7 +396,7 @@ void QMLManager::saveCloudCredentials()
 	}
 
 	if (!same_string(prefs.cloud_storage_password, qPrintable(cloudPwd))) {
-		free(prefs.cloud_storage_password);
+		free((void *)prefs.cloud_storage_password);
 		prefs.cloud_storage_password = strdup(qPrintable(cloudPwd));
 	}
 	if (cloudUser.isEmpty() || cloudPwd.isEmpty()) {
@@ -404,7 +404,7 @@ void QMLManager::saveCloudCredentials()
 	} else if (cloudCredentialsChanged) {
 		// let's make sure there are no unsaved changes
 		saveChangesLocal();
-		free(prefs.userid);
+		free((void *)prefs.userid);
 		prefs.userid = NULL;
 		syncLoadFromCloud();
 		QString url;
@@ -550,7 +550,7 @@ void QMLManager::retrieveUserid()
 	}
 	if (!userid.isEmpty()) {
 		// overwrite the existing userid
-		free(prefs.userid);
+		free((void *)prefs.userid);
 		prefs.userid = strdup(qPrintable(userid));
 		QSettings s;
 		s.setValue("subsurface_webservice_uid", prefs.userid);
@@ -649,9 +649,9 @@ void QMLManager::revertToNoCloudIfNeeded()
 			appendTextToLog(QStringLiteral("taking things back offline since sync with cloud failed"));
 			prefs.git_local_only = syncToCloud();
 		}
-		free(prefs.cloud_storage_email);
+		free((void *)prefs.cloud_storage_email);
 		prefs.cloud_storage_email = NULL;
-		free(prefs.cloud_storage_password);
+		free((void *)prefs.cloud_storage_password);
 		prefs.cloud_storage_password = NULL;
 		setCloudUserName("");
 		setCloudPassword("");