Fix incorrect error message reported for non-existent users

Previously, lookups of non-existent user names could return "Success";
it will now return "User does not exist" by resetting errno.  This also
centralizes the user name lookup code in libpgport.

Report and analysis by Nicolas Marchildon;  patch by me

12 files changed, 22 insertions, 95 deletions

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index e6bb132beaf..964d284bb66 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -770,15 +770,14 @@ exit_nicely(void)
 /*
  * find the current user
  *
- * on unix make sure it isn't really root
+ * on unix make sure it isn't root
  */
 static char *
 get_id(void)
 {
-#ifndef WIN32
-
-	struct passwd *pw;
+	const char	   *username;
 
+#ifndef WIN32
 	if (geteuid() == 0)			/* 0 is root's uid */
 	{
 		fprintf(stderr,
@@ -789,35 +788,11 @@ get_id(void)
 				progname);
 		exit(1);
 	}
-
-	pw = getpwuid(geteuid());
-	if (!pw)
-	{
-		fprintf(stderr,
-			  _("%s: could not obtain information about current user: %s\n"),
-				progname, strerror(errno));
-		exit(1);
-	}
-#else							/* the windows code */
-
-	struct passwd_win32
-	{
-		int			pw_uid;
-		char		pw_name[128];
-	}			pass_win32;
-	struct passwd_win32 *pw = &pass_win32;
-	DWORD		pwname_size = sizeof(pass_win32.pw_name) - 1;
-
-	pw->pw_uid = 1;
-	if (!GetUserName(pw->pw_name, &pwname_size))
-	{
-		fprintf(stderr, _("%s: could not get current user name: %s\n"),
-				progname, strerror(errno));
-		exit(1);
-	}
 #endif
 
-	return pg_strdup(pw->pw_name);
+	username = get_user_name_or_exit(progname);
+
+	return pg_strdup(username);
 }
 
 static char *
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 638d8cb5c31..d60a661543d 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -265,10 +265,13 @@ exec_command(const char *cmd,
 #ifndef WIN32
 			struct passwd *pw;
 
+			errno = 0;	/* clear errno before call */
 			pw = getpwuid(geteuid());
 			if (!pw)
 			{
-				psql_error("could not get home directory: %s\n", strerror(errno));
+				psql_error("could not get home directory for user id %d: %s\n",
+						   (int) geteuid(), errno ?
+						   strerror(errno) : "user does not exist");
 				exit(EXIT_FAILURE);
 			}
 			dir = pw->pw_dir;
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index 30530f2e37c..80b1ec0dfc7 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -8,9 +8,6 @@
 #include "postgres_fe.h"
 
 #ifndef WIN32
-#ifdef HAVE_PWD_H
-#include <pwd.h>				/* for getpwuid() */
-#endif
 #include <sys/types.h>			/* (ditto) */
 #include <unistd.h>				/* for geteuid() */
 #else
@@ -52,31 +49,18 @@ usage(void)
 {
 	const char *env;
 	const char *user;
-
-#ifndef WIN32
-	struct passwd *pw = NULL;
-#endif
+	char	   *errstr;
 
 	/* Find default user, in case we need it. */
 	user = getenv("PGUSER");
 	if (!user)
 	{
-#if !defined(WIN32) && !defined(__OS2__)
-		pw = getpwuid(geteuid());
-		if (pw)
-			user = pw->pw_name;
-		else
+		user = get_user_name(&errstr);
+		if (!user)
 		{
-			psql_error("could not get current user name: %s\n", strerror(errno));
+			psql_error("%s\n", errstr);
 			exit(EXIT_FAILURE);
 		}
-#else							/* WIN32 */
-		char		buf[128];
-		DWORD		bufsize = sizeof(buf) - 1;
-
-		if (GetUserName(buf, &bufsize))
-			user = buf;
-#endif   /* WIN32 */
 	}
 
 	printf(_("psql is the PostgreSQL interactive terminal.\n\n"));
diff --git a/src/bin/scripts/clusterdb.c b/src/bin/scripts/clusterdb.c
index cd54e8f47f7..e7065ce5df9 100644
--- a/src/bin/scripts/clusterdb.c
+++ b/src/bin/scripts/clusterdb.c
@@ -160,7 +160,7 @@ main(int argc, char *argv[])
 			else if (getenv("PGUSER"))
 				dbname = getenv("PGUSER");
 			else
-				dbname = get_user_name(progname);
+				dbname = get_user_name_or_exit(progname);
 		}
 
 		if (tables.head != NULL)
diff --git a/src/bin/scripts/common.c b/src/bin/scripts/common.c
index 4645bc137f9..e57e5207c6b 100644
--- a/src/bin/scripts/common.c
+++ b/src/bin/scripts/common.c
@@ -14,7 +14,6 @@
 
 #include "postgres_fe.h"
 
-#include <pwd.h>
 #include <signal.h>
 #include <unistd.h>
 
@@ -30,38 +29,6 @@ static CRITICAL_SECTION cancelConnLock;
 #endif
 
 /*
- * Returns the current user name.
- */
-const char *
-get_user_name(const char *progname)
-{
-#ifndef WIN32
-	struct passwd *pw;
-
-	pw = getpwuid(geteuid());
-	if (!pw)
-	{
-		fprintf(stderr, _("%s: could not obtain information about current user: %s\n"),
-				progname, strerror(errno));
-		exit(1);
-	}
-	return pw->pw_name;
-#else
-	static char username[128];	/* remains after function exit */
-	DWORD		len = sizeof(username) - 1;
-
-	if (!GetUserName(username, &len))
-	{
-		fprintf(stderr, _("%s: could not get current user name: %s\n"),
-				progname, strerror(errno));
-		exit(1);
-	}
-	return username;
-#endif
-}
-
-
-/*
  * Provide strictly harmonized handling of --help and --version
  * options.
  */
diff --git a/src/bin/scripts/common.h b/src/bin/scripts/common.h
index 6cf490f7484..a8a81f66b4b 100644
--- a/src/bin/scripts/common.h
+++ b/src/bin/scripts/common.h
@@ -22,8 +22,6 @@ enum trivalue
 
 typedef void (*help_handler) (const char *progname);
 
-extern const char *get_user_name(const char *progname);
-
 extern void handle_help_version_opts(int argc, char *argv[],
 						 const char *fixed_progname,
 						 help_handler hlp);
diff --git a/src/bin/scripts/createdb.c b/src/bin/scripts/createdb.c
index 14cd1284906..856a04d6485 100644
--- a/src/bin/scripts/createdb.c
+++ b/src/bin/scripts/createdb.c
@@ -174,7 +174,7 @@ main(int argc, char *argv[])
 		else if (getenv("PGUSER"))
 			dbname = getenv("PGUSER");
 		else
-			dbname = get_user_name(progname);
+			dbname = get_user_name_or_exit(progname);
 	}
 
 	initPQExpBuffer(&sql);
diff --git a/src/bin/scripts/createlang.c b/src/bin/scripts/createlang.c
index ff544a803d1..5cfba8e3d5a 100644
--- a/src/bin/scripts/createlang.c
+++ b/src/bin/scripts/createlang.c
@@ -127,7 +127,7 @@ main(int argc, char *argv[])
 		else if (getenv("PGUSER"))
 			dbname = getenv("PGUSER");
 		else
-			dbname = get_user_name(progname);
+			dbname = get_user_name_or_exit(progname);
 	}
 
 	initPQExpBuffer(&sql);
diff --git a/src/bin/scripts/createuser.c b/src/bin/scripts/createuser.c
index 61805917704..e3ce0dc455f 100644
--- a/src/bin/scripts/createuser.c
+++ b/src/bin/scripts/createuser.c
@@ -193,7 +193,7 @@ main(int argc, char *argv[])
 			if (getenv("PGUSER"))
 				newuser = getenv("PGUSER");
 			else
-				newuser = get_user_name(progname);
+				newuser = get_user_name_or_exit(progname);
 		}
 	}
 
diff --git a/src/bin/scripts/droplang.c b/src/bin/scripts/droplang.c
index de203173438..b9664a91850 100644
--- a/src/bin/scripts/droplang.c
+++ b/src/bin/scripts/droplang.c
@@ -126,7 +126,7 @@ main(int argc, char *argv[])
 		else if (getenv("PGUSER"))
 			dbname = getenv("PGUSER");
 		else
-			dbname = get_user_name(progname);
+			dbname = get_user_name_or_exit(progname);
 	}
 
 	initPQExpBuffer(&sql);
diff --git a/src/bin/scripts/reindexdb.c b/src/bin/scripts/reindexdb.c
index f7c09bebf8a..4e762ea56f4 100644
--- a/src/bin/scripts/reindexdb.c
+++ b/src/bin/scripts/reindexdb.c
@@ -188,7 +188,7 @@ main(int argc, char *argv[])
 			else if (getenv("PGUSER"))
 				dbname = getenv("PGUSER");
 			else
-				dbname = get_user_name(progname);
+				dbname = get_user_name_or_exit(progname);
 		}
 
 		reindex_system_catalogs(dbname, host, port, username, prompt_password,
@@ -203,7 +203,7 @@ main(int argc, char *argv[])
 			else if (getenv("PGUSER"))
 				dbname = getenv("PGUSER");
 			else
-				dbname = get_user_name(progname);
+				dbname = get_user_name_or_exit(progname);
 		}
 
 		if (indexes.head != NULL)
diff --git a/src/bin/scripts/vacuumdb.c b/src/bin/scripts/vacuumdb.c
index 616d9339e1e..8970ec6ad2e 100644
--- a/src/bin/scripts/vacuumdb.c
+++ b/src/bin/scripts/vacuumdb.c
@@ -202,7 +202,7 @@ main(int argc, char *argv[])
 			else if (getenv("PGUSER"))
 				dbname = getenv("PGUSER");
 			else
-				dbname = get_user_name(progname);
+				dbname = get_user_name_or_exit(progname);
 		}
 
 		if (tables.head != NULL)