ALTER SYSTEM SET typos and fix for temporary file name management

commit a8cf33deb3c46c4f56f1e617bbd3142cbbd66f1b
Author: Michael Paquier <michael@otacoo.com>
Date:   Tue Jan 21 21:44:30 2014 +0900

    Fix typos and temporary file management in ALTER SYSTEM
    
    Using a temporary file uniquely defined in a single place reduces the
    occurence of bugs related to it. Some typos are fixed at the same time.

diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index fc35f5b..a31bcdf 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -834,11 +834,10 @@ sendDir(char *path, int basepathlen, bool sizeonly, List *tablespaces)
 
 		/* skip auto conf temporary file */
 		if (strncmp(de->d_name,
-					PG_AUTOCONF_FILENAME ".temp",
-					sizeof(PG_AUTOCONF_FILENAME) + 4) == 0)
+					PG_AUTOCONF_FILENAME_TEMP,
+					sizeof(PG_AUTOCONF_FILENAME_TEMP)) == 0)
 			continue;
 
-
 		/*
 		 * If there's a backup_label file, it belongs to a backup started by
 		 * the user with pg_start_backup(). It is *not* correct for this
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 1217098..7da52bf 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -6457,9 +6457,9 @@ flatten_set_variable_args(const char *name, List *args)
 }
 
 /*
- * Writes updated configuration parameter values into
- * postgresql.auto.conf.temp file. It traverses the list of parameters
- * and quote the string values before writing them to temporaray file.
+ * Write updated configuration parameter values into
+ * file PG_AUTOCONF_FILENAME_TEMP. It traverses the list of parameters
+ * and quotes the string values before writing them to temporary file.
  */
 static void
 write_auto_conf_file(int fd, const char *filename, ConfigVariable **head_p)
@@ -6468,8 +6468,8 @@ write_auto_conf_file(int fd, const char *filename, ConfigVariable **head_p)
 	StringInfoData buf;
 
 	initStringInfo(&buf);
-	appendStringInfoString(&buf, "# Do not edit this file manually! \n");
-	appendStringInfoString(&buf, "# It will be overwritten by ALTER SYSTEM command. \n");
+	appendStringInfoString(&buf, "# Do not edit this file manually!\n");
+	appendStringInfoString(&buf, "# It will be overwritten by ALTER SYSTEM command.\n");
 
 	/*
 	 * write the file header message before contents, so that if there is no
@@ -6596,7 +6596,7 @@ replace_auto_config_value(ConfigVariable **head_p, ConfigVariable **tail_p,
  *
  * The configuration parameters are written to a temporary
  * file then renamed to the final name. The template for the
- * temporary file is postgresql.auto.conf.temp.
+ * temporary file is PG_AUTOCONF_FILENAME_TEMP.
  *
  * An LWLock is used to serialize writing to the same file.
  *
@@ -6662,16 +6662,16 @@ AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
 		ereport(ERROR,
 				(errmsg("invalid value for parameter \"%s\": \"%s\"", name, value)));
 
-
 	/*
 	 * Use data directory as reference path for postgresql.auto.conf and it's
-	 * corresponding temp file
+	 * corresponding temp file.
 	 */
-	join_path_components(AutoConfFileName, data_directory, PG_AUTOCONF_FILENAME);
+	join_path_components(AutoConfFileName, data_directory,
+						 PG_AUTOCONF_FILENAME);
 	canonicalize_path(AutoConfFileName);
-	snprintf(AutoConfTmpFileName, sizeof(AutoConfTmpFileName), "%s.%s",
-			 AutoConfFileName,
-			 "temp");
+	join_path_components(AutoConfTmpFileName, data_directory,
+						 PG_AUTOCONF_FILENAME_TEMP);
+	canonicalize_path(AutoConfTmpFileName);
 
 	/*
 	 * one backend is allowed to operate on postgresql.auto.conf file, to
@@ -6713,7 +6713,7 @@ AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
 		 */
 		replace_auto_config_value(&head, &tail, AutoConfFileName, name, value);
 
-		/* Write and sync the New contents to postgresql.auto.conf.temp file */
+		/* Write and sync the New contents to file PG_AUTOCONF_FILENAME_TEMP */
 		write_auto_conf_file(Tmpfd, AutoConfTmpFileName, &head);
 
 		close(Tmpfd);
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 7e934b7..6b5302f 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -1300,8 +1300,8 @@ setup_config(void)
 	 * file will override the value of parameters that exists before parse of
 	 * this file.
 	 */
-	autoconflines[0] = pg_strdup("# Do not edit this file manually! \n");
-	autoconflines[1] = pg_strdup("# It will be overwritten by the ALTER SYSTEM command. \n");
+	autoconflines[0] = pg_strdup("# Do not edit this file manually!\n");
+	autoconflines[1] = pg_strdup("# It will be overwritten by the ALTER SYSTEM command.\n");
 	autoconflines[2] = NULL;
 
 	sprintf(path, "%s/%s", pg_data, PG_AUTOCONF_FILENAME);
diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h
index 20c5ff0..a4c2e3f 100644
--- a/src/include/pg_config_manual.h
+++ b/src/include/pg_config_manual.h
@@ -304,6 +304,12 @@
 /*
  * Automatic configuration file name for ALTER SYSTEM.
  * This file will be used to store values of configuration parameters
- * set by ALTER SYSTEM command
+ * set by ALTER SYSTEM command.
  */
 #define PG_AUTOCONF_FILENAME		"postgresql.auto.conf"
+
+/*
+ * This file will be used to store values in a temporary file
+ * when modifications occur with ALTER SYSTEM command.
+ */
+#define PG_AUTOCONF_FILENAME_TEMP	"postgresql.auto.conf.temp"

*** a/src/backend/utils/misc/guc-file.l
--- b/src/backend/utils/misc/guc-file.l
***************
*** 149,155 **** ProcessConfigFile(GucContext context)
  	}
  
  	/*
! 	 * Parse postgresql.auto.conf file after postgresql.conf to replace
  	 * parameters set by ALTER SYSTEM command. This file is present in
  	 * data directory, however when called during initdb data directory is not
  	 * set till this point, so use ConfigFile path which will be same.
--- 149,155 ----
  	}
  
  	/*
! 	 * Parse file PG_AUTOCONF_FILENAME after postgresql.conf to replace
  	 * parameters set by ALTER SYSTEM command. This file is present in
  	 * data directory, however when called during initdb data directory is not
  	 * set till this point, so use ConfigFile path which will be same.
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 6457,6465 **** flatten_set_variable_args(const char *name, List *args)
  }
  
  /*
!  * Writes updated configuration parameter values into
!  * postgresql.auto.conf.temp file. It traverses the list of parameters
!  * and quote the string values before writing them to temporaray file.
   */
  static void
  write_auto_conf_file(int fd, const char *filename, ConfigVariable **head_p)
--- 6457,6465 ----
  }
  
  /*
!  * Write updated configuration parameter values into a temporary file.
!  * this function traverses the list of parameters and quotes the string
!  * values before writing them.
   */
  static void
  write_auto_conf_file(int fd, const char *filename, ConfigVariable **head_p)
***************
*** 6468,6475 **** write_auto_conf_file(int fd, const char *filename, ConfigVariable **head_p)
  	StringInfoData buf;
  
  	initStringInfo(&buf);
! 	appendStringInfoString(&buf, "# Do not edit this file manually! \n");
! 	appendStringInfoString(&buf, "# It will be overwritten by ALTER SYSTEM command. \n");
  
  	/*
  	 * write the file header message before contents, so that if there is no
--- 6468,6475 ----
  	StringInfoData buf;
  
  	initStringInfo(&buf);
! 	appendStringInfoString(&buf, "# Do not edit this file manually!\n");
! 	appendStringInfoString(&buf, "# It will be overwritten by ALTER SYSTEM command.\n");
  
  	/*
  	 * write the file header message before contents, so that if there is no
***************
*** 6517,6523 **** write_auto_conf_file(int fd, const char *filename, ConfigVariable **head_p)
  
  /*
   * This function takes list of all configuration parameters in
!  * postgresql.auto.conf and parameter to be updated as input arguments and
   * replace the updated configuration parameter value in a list. If the
   * parameter to be updated is new then it is appended to the list of
   * parameters.
--- 6517,6523 ----
  
  /*
   * This function takes list of all configuration parameters in
!  * PG_AUTOCONF_FILENAME and parameter to be updated as input arguments and
   * replace the updated configuration parameter value in a list. If the
   * parameter to be updated is new then it is appended to the list of
   * parameters.
***************
*** 6595,6607 **** replace_auto_config_value(ConfigVariable **head_p, ConfigVariable **tail_p,
   * and write them all to the automatic configuration file.
   *
   * The configuration parameters are written to a temporary
!  * file then renamed to the final name. The template for the
!  * temporary file is postgresql.auto.conf.temp.
   *
   * An LWLock is used to serialize writing to the same file.
   *
   * In case of an error, we leave the original automatic
!  * configuration file (postgresql.auto.conf) intact.
   */
  void
  AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
--- 6595,6606 ----
   * and write them all to the automatic configuration file.
   *
   * The configuration parameters are written to a temporary
!  * file then renamed to the final name.
   *
   * An LWLock is used to serialize writing to the same file.
   *
   * In case of an error, we leave the original automatic
!  * configuration file (PG_AUTOCONF_FILENAME) intact.
   */
  void
  AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
***************
*** 6664,6671 **** AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
  
  
  	/*
! 	 * Use data directory as reference path for postgresql.auto.conf and it's
! 	 * corresponding temp file
  	 */
  	join_path_components(AutoConfFileName, data_directory, PG_AUTOCONF_FILENAME);
  	canonicalize_path(AutoConfFileName);
--- 6663,6670 ----
  
  
  	/*
! 	 * Use data directory as reference path for PG_AUTOCONF_FILENAME and its
! 	 * corresponding temporary file.
  	 */
  	join_path_components(AutoConfFileName, data_directory, PG_AUTOCONF_FILENAME);
  	canonicalize_path(AutoConfFileName);
***************
*** 6674,6683 **** AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
  			 "temp");
  
  	/*
! 	 * one backend is allowed to operate on postgresql.auto.conf file, to
  	 * ensure that we need to update the contents of the file with
  	 * AutoFileLock. To ensure crash safety, first the contents are written to
! 	 * temporary file and then rename it to postgresql.auto.conf. In case
  	 * there exists a temp file from previous crash, that can be reused.
  	 */
  
--- 6673,6682 ----
  			 "temp");
  
  	/*
! 	 * One backend is allowed to operate on file PG_AUTOCONF_FILENAME, to
  	 * ensure that we need to update the contents of the file with
  	 * AutoFileLock. To ensure crash safety, first the contents are written to
! 	 * a temporary file which is then renameed to PG_AUTOCONF_FILENAME. In case
  	 * there exists a temp file from previous crash, that can be reused.
  	 */
  
***************
*** 6694,6707 **** AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
  	{
  		if (stat(AutoConfFileName, &st) == 0)
  		{
! 			/* open postgresql.auto.conf file */
  			infile = AllocateFile(AutoConfFileName, "r");
  			if (infile == NULL)
  				ereport(ERROR,
  						(errmsg("failed to open auto conf file \"%s\": %m ",
  								AutoConfFileName)));
  
! 			/* Parse the postgresql.auto.conf file */
  			ParseConfigFp(infile, AutoConfFileName, 0, LOG, &head, &tail);
  
  			FreeFile(infile);
--- 6693,6706 ----
  	{
  		if (stat(AutoConfFileName, &st) == 0)
  		{
! 			/* open file PG_AUTOCONF_FILENAME */
  			infile = AllocateFile(AutoConfFileName, "r");
  			if (infile == NULL)
  				ereport(ERROR,
  						(errmsg("failed to open auto conf file \"%s\": %m ",
  								AutoConfFileName)));
  
! 			/* parse it */
  			ParseConfigFp(infile, AutoConfFileName, 0, LOG, &head, &tail);
  
  			FreeFile(infile);
***************
*** 6713,6719 **** AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
  		 */
  		replace_auto_config_value(&head, &tail, AutoConfFileName, name, value);
  
! 		/* Write and sync the New contents to postgresql.auto.conf.temp file */
  		write_auto_conf_file(Tmpfd, AutoConfTmpFileName, &head);
  
  		close(Tmpfd);
--- 6712,6718 ----
  		 */
  		replace_auto_config_value(&head, &tail, AutoConfFileName, name, value);
  
! 		/* Write and sync the new contents to the temporary file */
  		write_auto_conf_file(Tmpfd, AutoConfTmpFileName, &head);
  
  		close(Tmpfd);
*** a/src/bin/initdb/initdb.c
--- b/src/bin/initdb/initdb.c
***************
*** 1300,1307 **** setup_config(void)
  	 * file will override the value of parameters that exists before parse of
  	 * this file.
  	 */
! 	autoconflines[0] = pg_strdup("# Do not edit this file manually! \n");
! 	autoconflines[1] = pg_strdup("# It will be overwritten by the ALTER SYSTEM command. \n");
  	autoconflines[2] = NULL;
  
  	sprintf(path, "%s/%s", pg_data, PG_AUTOCONF_FILENAME);
--- 1300,1307 ----
  	 * file will override the value of parameters that exists before parse of
  	 * this file.
  	 */
! 	autoconflines[0] = pg_strdup("# Do not edit this file manually!\n");
! 	autoconflines[1] = pg_strdup("# It will be overwritten by the ALTER SYSTEM command.\n");
  	autoconflines[2] = NULL;
  
  	sprintf(path, "%s/%s", pg_data, PG_AUTOCONF_FILENAME);
*** a/src/include/pg_config_manual.h
--- b/src/include/pg_config_manual.h
***************
*** 304,309 ****
  /*
   * Automatic configuration file name for ALTER SYSTEM.
   * This file will be used to store values of configuration parameters
!  * set by ALTER SYSTEM command
   */
  #define PG_AUTOCONF_FILENAME		"postgresql.auto.conf"
--- 304,309 ----
  /*
   * Automatic configuration file name for ALTER SYSTEM.
   * This file will be used to store values of configuration parameters
!  * set by ALTER SYSTEM command.
   */
  #define PG_AUTOCONF_FILENAME		"postgresql.auto.conf"

*** a/src/backend/replication/basebackup.c
--- b/src/backend/replication/basebackup.c
***************
*** 834,840 **** sendDir(char *path, int basepathlen, bool sizeonly, List *tablespaces)
  
  		/* skip auto conf temporary file */
  		if (strncmp(de->d_name,
! 					PG_AUTOCONF_FILENAME ".temp",
  					sizeof(PG_AUTOCONF_FILENAME) + 4) == 0)
  			continue;
  
--- 834,840 ----
  
  		/* skip auto conf temporary file */
  		if (strncmp(de->d_name,
! 					PG_AUTOCONF_FILENAME ".tmp",
  					sizeof(PG_AUTOCONF_FILENAME) + 4) == 0)
  			continue;
  
*** a/src/backend/utils/misc/guc.c
--- b/src/backend/utils/misc/guc.c
***************
*** 6671,6677 **** AlterSystemSetConfigFile(AlterSystemStmt * altersysstmt)
  	canonicalize_path(AutoConfFileName);
  	snprintf(AutoConfTmpFileName, sizeof(AutoConfTmpFileName), "%s.%s",
  			 AutoConfFileName,
! 			 "temp");
  
  	/*
  	 * one backend is allowed to operate on postgresql.auto.conf file, to
--- 6671,6677 ----
  	canonicalize_path(AutoConfFileName);
  	snprintf(AutoConfTmpFileName, sizeof(AutoConfTmpFileName), "%s.%s",
  			 AutoConfFileName,
! 			 "tmp");
  
  	/*
  	 * one backend is allowed to operate on postgresql.auto.conf file, to