Remove redundant null pointer checks before free()

Per applicable standards, free() with a null pointer is a no-op.
Systems that don't observe that are ancient and no longer relevant.
Some PostgreSQL code already required this behavior, so this change
does not introduce any new requirements, just makes the code more
consistent.

Discussion: https://www.postgresql.org/message-id/flat/dac5d2d0-98f5-94d9-8e69-46da2413593d%40enterprisedb.com

1 files changed, 70 insertions, 141 deletions

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 6e936bbff30..057c9da0ede 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -540,8 +540,7 @@ pqFreeCommandQueue(PGcmdQueueEntry *queue)
 		PGcmdQueueEntry *cur = queue;
 
 		queue = cur->next;
-		if (cur->query)
-			free(cur->query);
+		free(cur->query);
 		free(cur);
 	}
 }
@@ -593,8 +592,7 @@ pqDropServerData(PGconn *conn)
 	conn->sversion = 0;
 
 	/* Drop large-object lookup data */
-	if (conn->lobjfuncs)
-		free(conn->lobjfuncs);
+	free(conn->lobjfuncs);
 	conn->lobjfuncs = NULL;
 
 	/* Reset assorted other per-connection state */
@@ -602,8 +600,7 @@ pqDropServerData(PGconn *conn)
 	conn->auth_req_received = false;
 	conn->password_needed = false;
 	conn->write_failed = false;
-	if (conn->write_err_msg)
-		free(conn->write_err_msg);
+	free(conn->write_err_msg);
 	conn->write_err_msg = NULL;
 	conn->be_pid = 0;
 	conn->be_key = 0;
@@ -898,8 +895,7 @@ fillPGconn(PGconn *conn, PQconninfoOption *connOptions)
 			{
 				char	  **connmember = (char **) ((char *) conn + option->connofs);
 
-				if (*connmember)
-					free(*connmember);
+				free(*connmember);
 				*connmember = strdup(tmp);
 				if (*connmember == NULL)
 				{
@@ -1113,8 +1109,7 @@ connectOptions2(PGconn *conn)
 		}
 		else
 		{
-			if (ch->host)
-				free(ch->host);
+			free(ch->host);
 
 			/*
 			 * This bit selects the default host location.  If you change
@@ -1186,8 +1181,7 @@ connectOptions2(PGconn *conn)
 	 */
 	if (conn->pguser == NULL || conn->pguser[0] == '\0')
 	{
-		if (conn->pguser)
-			free(conn->pguser);
+		free(conn->pguser);
 		conn->pguser = pg_fe_getauthname(&conn->errorMessage);
 		if (!conn->pguser)
 		{
@@ -1201,8 +1195,7 @@ connectOptions2(PGconn *conn)
 	 */
 	if (conn->dbName == NULL || conn->dbName[0] == '\0')
 	{
-		if (conn->dbName)
-			free(conn->dbName);
+		free(conn->dbName);
 		conn->dbName = strdup(conn->pguser);
 		if (!conn->dbName)
 			goto oom_error;
@@ -1221,8 +1214,7 @@ connectOptions2(PGconn *conn)
 
 			if (pqGetHomeDirectory(homedir, sizeof(homedir)))
 			{
-				if (conn->pgpassfile)
-					free(conn->pgpassfile);
+				free(conn->pgpassfile);
 				conn->pgpassfile = malloc(MAXPGPATH);
 				if (!conn->pgpassfile)
 					goto oom_error;
@@ -1548,8 +1540,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 		/* Insert dbName parameter value into struct */
 		if (dbName && dbName[0] != '\0')
 		{
-			if (conn->dbName)
-				free(conn->dbName);
+			free(conn->dbName);
 			conn->dbName = strdup(dbName);
 			if (!conn->dbName)
 				goto oom_error;
@@ -1562,8 +1553,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 	 */
 	if (pghost && pghost[0] != '\0')
 	{
-		if (conn->pghost)
-			free(conn->pghost);
+		free(conn->pghost);
 		conn->pghost = strdup(pghost);
 		if (!conn->pghost)
 			goto oom_error;
@@ -1571,8 +1561,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 
 	if (pgport && pgport[0] != '\0')
 	{
-		if (conn->pgport)
-			free(conn->pgport);
+		free(conn->pgport);
 		conn->pgport = strdup(pgport);
 		if (!conn->pgport)
 			goto oom_error;
@@ -1580,8 +1569,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 
 	if (pgoptions && pgoptions[0] != '\0')
 	{
-		if (conn->pgoptions)
-			free(conn->pgoptions);
+		free(conn->pgoptions);
 		conn->pgoptions = strdup(pgoptions);
 		if (!conn->pgoptions)
 			goto oom_error;
@@ -1589,8 +1577,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 
 	if (login && login[0] != '\0')
 	{
-		if (conn->pguser)
-			free(conn->pguser);
+		free(conn->pguser);
 		conn->pguser = strdup(login);
 		if (!conn->pguser)
 			goto oom_error;
@@ -1598,8 +1585,7 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 
 	if (pwd && pwd[0] != '\0')
 	{
-		if (conn->pgpass)
-			free(conn->pgpass);
+		free(conn->pgpass);
 		conn->pgpass = strdup(pwd);
 		if (!conn->pgpass)
 			goto oom_error;
@@ -4044,10 +4030,8 @@ makeEmptyPGconn(void)
 static void
 freePGconn(PGconn *conn)
 {
-	int			i;
-
 	/* let any event procs clean up their state data */
-	for (i = 0; i < conn->nEvents; i++)
+	for (int i = 0; i < conn->nEvents; i++)
 	{
 		PGEventConnDestroy evt;
 
@@ -4058,114 +4042,69 @@ freePGconn(PGconn *conn)
 	}
 
 	/* clean up pg_conn_host structures */
-	if (conn->connhost != NULL)
+	for (int i = 0; i < conn->nconnhost; ++i)
 	{
-		for (i = 0; i < conn->nconnhost; ++i)
+		free(conn->connhost[i].host);
+		free(conn->connhost[i].hostaddr);
+		free(conn->connhost[i].port);
+		if (conn->connhost[i].password != NULL)
 		{
-			if (conn->connhost[i].host != NULL)
-				free(conn->connhost[i].host);
-			if (conn->connhost[i].hostaddr != NULL)
-				free(conn->connhost[i].hostaddr);
-			if (conn->connhost[i].port != NULL)
-				free(conn->connhost[i].port);
-			if (conn->connhost[i].password != NULL)
-			{
-				explicit_bzero(conn->connhost[i].password, strlen(conn->connhost[i].password));
-				free(conn->connhost[i].password);
-			}
+			explicit_bzero(conn->connhost[i].password, strlen(conn->connhost[i].password));
+			free(conn->connhost[i].password);
 		}
-		free(conn->connhost);
 	}
-
-	if (conn->client_encoding_initial)
-		free(conn->client_encoding_initial);
-	if (conn->events)
-		free(conn->events);
-	if (conn->pghost)
-		free(conn->pghost);
-	if (conn->pghostaddr)
-		free(conn->pghostaddr);
-	if (conn->pgport)
-		free(conn->pgport);
-	if (conn->connect_timeout)
-		free(conn->connect_timeout);
-	if (conn->pgtcp_user_timeout)
-		free(conn->pgtcp_user_timeout);
-	if (conn->pgoptions)
-		free(conn->pgoptions);
-	if (conn->appname)
-		free(conn->appname);
-	if (conn->fbappname)
-		free(conn->fbappname);
-	if (conn->dbName)
-		free(conn->dbName);
-	if (conn->replication)
-		free(conn->replication);
-	if (conn->pguser)
-		free(conn->pguser);
+	free(conn->connhost);
+
+	free(conn->client_encoding_initial);
+	free(conn->events);
+	free(conn->pghost);
+	free(conn->pghostaddr);
+	free(conn->pgport);
+	free(conn->connect_timeout);
+	free(conn->pgtcp_user_timeout);
+	free(conn->pgoptions);
+	free(conn->appname);
+	free(conn->fbappname);
+	free(conn->dbName);
+	free(conn->replication);
+	free(conn->pguser);
 	if (conn->pgpass)
 	{
 		explicit_bzero(conn->pgpass, strlen(conn->pgpass));
 		free(conn->pgpass);
 	}
-	if (conn->pgpassfile)
-		free(conn->pgpassfile);
-	if (conn->channel_binding)
-		free(conn->channel_binding);
-	if (conn->keepalives)
-		free(conn->keepalives);
-	if (conn->keepalives_idle)
-		free(conn->keepalives_idle);
-	if (conn->keepalives_interval)
-		free(conn->keepalives_interval);
-	if (conn->keepalives_count)
-		free(conn->keepalives_count);
-	if (conn->sslmode)
-		free(conn->sslmode);
-	if (conn->sslcert)
-		free(conn->sslcert);
-	if (conn->sslkey)
-		free(conn->sslkey);
+	free(conn->pgpassfile);
+	free(conn->channel_binding);
+	free(conn->keepalives);
+	free(conn->keepalives_idle);
+	free(conn->keepalives_interval);
+	free(conn->keepalives_count);
+	free(conn->sslmode);
+	free(conn->sslcert);
+	free(conn->sslkey);
 	if (conn->sslpassword)
 	{
 		explicit_bzero(conn->sslpassword, strlen(conn->sslpassword));
 		free(conn->sslpassword);
 	}
-	if (conn->sslrootcert)
-		free(conn->sslrootcert);
-	if (conn->sslcrl)
-		free(conn->sslcrl);
-	if (conn->sslcrldir)
-		free(conn->sslcrldir);
-	if (conn->sslcompression)
-		free(conn->sslcompression);
-	if (conn->sslsni)
-		free(conn->sslsni);
-	if (conn->requirepeer)
-		free(conn->requirepeer);
-	if (conn->ssl_min_protocol_version)
-		free(conn->ssl_min_protocol_version);
-	if (conn->ssl_max_protocol_version)
-		free(conn->ssl_max_protocol_version);
-	if (conn->gssencmode)
-		free(conn->gssencmode);
-	if (conn->krbsrvname)
-		free(conn->krbsrvname);
-	if (conn->gsslib)
-		free(conn->gsslib);
-	if (conn->connip)
-		free(conn->connip);
+	free(conn->sslrootcert);
+	free(conn->sslcrl);
+	free(conn->sslcrldir);
+	free(conn->sslcompression);
+	free(conn->sslsni);
+	free(conn->requirepeer);
+	free(conn->ssl_min_protocol_version);
+	free(conn->ssl_max_protocol_version);
+	free(conn->gssencmode);
+	free(conn->krbsrvname);
+	free(conn->gsslib);
+	free(conn->connip);
 	/* Note that conn->Pfdebug is not ours to close or free */
-	if (conn->write_err_msg)
-		free(conn->write_err_msg);
-	if (conn->inBuffer)
-		free(conn->inBuffer);
-	if (conn->outBuffer)
-		free(conn->outBuffer);
-	if (conn->rowBuf)
-		free(conn->rowBuf);
-	if (conn->target_session_attrs)
-		free(conn->target_session_attrs);
+	free(conn->write_err_msg);
+	free(conn->inBuffer);
+	free(conn->outBuffer);
+	free(conn->rowBuf);
+	free(conn->target_session_attrs);
 	termPQExpBuffer(&conn->errorMessage);
 	termPQExpBuffer(&conn->workBuffer);
 
@@ -4433,8 +4372,7 @@ fail:
 void
 PQfreeCancel(PGcancel *cancel)
 {
-	if (cancel)
-		free(cancel);
+	free(cancel);
 }
 
 
@@ -5883,8 +5821,7 @@ conninfo_array_parse(const char *const *keywords, const char *const *values,
 						{
 							if (strcmp(options[k].keyword, str_option->keyword) == 0)
 							{
-								if (options[k].val)
-									free(options[k].val);
+								free(options[k].val);
 								options[k].val = strdup(str_option->val);
 								if (!options[k].val)
 								{
@@ -5912,8 +5849,7 @@ conninfo_array_parse(const char *const *keywords, const char *const *values,
 				/*
 				 * Store the value, overriding previous settings
 				 */
-				if (option->val)
-					free(option->val);
+				free(option->val);
 				option->val = strdup(pvalue);
 				if (!option->val)
 				{
@@ -6344,8 +6280,7 @@ conninfo_uri_parse_options(PQconninfoOption *options, const char *uri,
 cleanup:
 	termPQExpBuffer(&hostbuf);
 	termPQExpBuffer(&portbuf);
-	if (buf)
-		free(buf);
+	free(buf);
 	return retval;
 }
 
@@ -6655,8 +6590,7 @@ conninfo_storeval(PQconninfoOption *connOptions,
 		}
 	}
 
-	if (option->val)
-		free(option->val);
+	free(option->val);
 	option->val = value_copy;
 
 	return option;
@@ -6735,16 +6669,11 @@ PQconninfo(PGconn *conn)
 void
 PQconninfoFree(PQconninfoOption *connOptions)
 {
-	PQconninfoOption *option;
-
 	if (connOptions == NULL)
 		return;
 
-	for (option = connOptions; option->keyword != NULL; option++)
-	{
-		if (option->val != NULL)
-			free(option->val);
-	}
+	for (PQconninfoOption *option = connOptions; option->keyword != NULL; option++)
+		free(option->val);
 	free(connOptions);
 }