Fix failures to ignore \r when reading Windows-style newlines.

libpq failed to ignore Windows-style newlines in connection service files.
This normally wasn't a problem on Windows itself, because fgets() would
convert \r\n to just \n.  But if libpq were running inside a program that
changes the default fopen mode to binary, it would see the \r's and think
they were data.  In any case, it's project policy to ignore \r in text
files unconditionally, because people sometimes try to use files with
DOS-style newlines on Unix machines, where the C library won't hide that
from us.

Hence, adjust parseServiceFile() to ignore \r as well as \n at the end of
the line.  In HEAD, go a little further and make it ignore all trailing
whitespace, to match what it's always done with leading whitespace.

In HEAD, also run around and fix up everyplace where we have
newline-chomping code to make all those places look consistent and
uniformly drop \r.  It is not clear whether any of those changes are
fixing live bugs.  Most of the non-cosmetic changes are in places that
are reading popen output, and the jury is still out as to whether popen
on Windows can return \r\n.  (The Windows-specific code in pipe_read_line
seems to think so, but our lack of support for this elsewhere suggests
maybe it's not a problem in practice.)  Hence, I desisted from applying
those changes to back branches, except in run_ssl_passphrase_command()
which is new enough and little-tested enough that we'd probably not have
heard about any problems there.

Tom Lane and Michael Paquier, per bug #15827 from Jorge Gustavo Rocha.
Back-patch the parseServiceFile() change to all supported branches,
and the run_ssl_passphrase_command() change to v11 where that was added.

Discussion: https://postgr.es/m/15827-e6ba53a3a7ed543c@postgresql.org

src/backend/libpq/be-secure-common.c

@@ -112,9 +112,10 @@ run_ssl_passphrase_command(const char *prompt, bool is_server_start, char *buf,
 		goto error;
 	}
 
-	/* strip trailing newline */
+	/* strip trailing newline, including \r in case we're on Windows */
 	len = strlen(buf);
-	if (len > 0 && buf[len - 1] == '\n')
+	while (len > 0 && (buf[len - 1] == '\n' ||
+					   buf[len - 1] == '\r'))
 		buf[--len] = '\0';
 
 error:

src/bin/pg_ctl/pg_ctl.c

@@ -2176,6 +2176,7 @@ adjust_data_dir(void)
 				filename[MAXPGPATH],
 			   *my_exec_path;
 	FILE	   *fd;
+	int			len;
 
 	/* do nothing if we're working without knowledge of data dir */
 	if (pg_config == NULL)
@@ -2218,9 +2219,12 @@ adjust_data_dir(void)
 	pclose(fd);
 	free(my_exec_path);
 
-	/* Remove trailing newline */
-	if (strchr(filename, '\n') != NULL)
-		*strchr(filename, '\n') = '\0';
+	/* Remove trailing newline, handling Windows newlines as well */
+	len = strlen(filename);
+	while (len > 0 &&
+		   (filename[len - 1] == '\n' ||
+			filename[len - 1] == '\r'))
+		filename[--len] = '\0';
 
 	free(pg_data);
 	pg_data = pg_strdup(filename);

src/bin/pg_resetwal/pg_resetwal.c

@@ -559,12 +559,10 @@ CheckDataVersion(void)
 
 	/* remove trailing newline, handling Windows newlines as well */
 	len = strlen(rawline);
-	if (len > 0 && rawline[len - 1] == '\n')
-	{
+	while (len > 0 &&
+		   (rawline[len - 1] == '\n' ||
+			rawline[len - 1] == '\r'))
 		rawline[--len] = '\0';
-		if (len > 0 && rawline[len - 1] == '\r')
-			rawline[--len] = '\0';
-	}
 
 	if (strcmp(rawline, PG_MAJORVERSION) != 0)
 	{

src/bin/pg_upgrade/option.c

@@ -405,6 +405,7 @@ adjust_data_dir(ClusterInfo *cluster)
 				cmd_output[MAX_STRING];
 	FILE	   *fp,
 			   *output;
+	int			len;
 
 	/* Initially assume config dir and data dir are the same */
 	cluster->pgconfig = pg_strdup(cluster->pgdata);
@@ -445,9 +446,12 @@ adjust_data_dir(ClusterInfo *cluster)
 
 	pclose(output);
 
-	/* Remove trailing newline */
-	if (strchr(cmd_output, '\n') != NULL)
-		*strchr(cmd_output, '\n') = '\0';
+	/* Remove trailing newline, handling Windows newlines as well */
+	len = strlen(cmd_output);
+	while (len > 0 &&
+		   (cmd_output[len - 1] == '\n' ||
+			cmd_output[len - 1] == '\r'))
+		cmd_output[--len] = '\0';
 
 	cluster->pgdata = pg_strdup(cmd_output);
 
@@ -508,10 +512,15 @@ get_sock_dir(ClusterInfo *cluster, bool live_check)
 					sscanf(line, "%hu", &old_cluster.port);
 				if (lineno == LOCK_FILE_LINE_SOCKET_DIR)
 				{
+					int			len;
+
 					cluster->sockdir = pg_strdup(line);
-					/* strip off newline */
-					if (strchr(cluster->sockdir, '\n') != NULL)
-						*strchr(cluster->sockdir, '\n') = '\0';
+					/* strip off newline, handling Windows newlines as well */
+					len = strlen(cluster->sockdir);
+					while (len > 0 &&
+						   (cluster->sockdir[len - 1] == '\n' ||
+							cluster->sockdir[len - 1] == '\r'))
+						cluster->sockdir[--len] = '\0';
 				}
 			}
 			fclose(fp);

src/bin/psql/prompt.c

@@ -264,6 +264,7 @@ get_prompt(promptStatus_t status, ConditionalStack cstack)
 						FILE	   *fd;
 						char	   *file = pg_strdup(p + 1);
 						int			cmdend;
+						int			buflen;
 
 						cmdend = strcspn(file, "`");
 						file[cmdend] = '\0';
@@ -274,8 +275,10 @@ get_prompt(promptStatus_t status, ConditionalStack cstack)
 								buf[0] = '\0';
 							pclose(fd);
 						}
-						if (strlen(buf) > 0 && buf[strlen(buf) - 1] == '\n')
-							buf[strlen(buf) - 1] = '\0';
+						buflen = strlen(buf);
+						while (buflen > 0 && (buf[buflen - 1] == '\n' ||
+											  buf[buflen - 1] == '\r'))
+							buf[--buflen] = '\0';
 						free(file);
 						p += cmdend + 1;
 						break;

src/interfaces/libpq/fe-connect.c

@@ -5020,6 +5020,8 @@ parseServiceFile(const char *serviceFile,
 
 	while ((line = fgets(buf, sizeof(buf), f)) != NULL)
 	{
+		int			len;
+
 		linenr++;
 
 		if (strlen(line) >= sizeof(buf) - 1)
@@ -5032,16 +5034,17 @@ parseServiceFile(const char *serviceFile,
 			return 2;
 		}
 
-		/* ignore EOL at end of line */
-		if (strlen(line) && line[strlen(line) - 1] == '\n')
-			line[strlen(line) - 1] = 0;
+		/* ignore whitespace at end of line, especially the newline */
+		len = strlen(line);
+		while (len > 0 && isspace((unsigned char) line[len - 1]))
+			line[--len] = '\0';
 
-		/* ignore leading blanks */
+		/* ignore leading whitespace too */
 		while (*line && isspace((unsigned char) line[0]))
 			line++;
 
 		/* ignore comments and empty lines */
-		if (strlen(line) == 0 || line[0] == '#')
+		if (line[0] == '\0' || line[0] == '#')
 			continue;
 
 		/* Check for right groupname */
@@ -6910,14 +6913,10 @@ passwordFromFile(const char *hostname, const char *port, const char *dbname,
 
 		len = strlen(buf);
 
-		/* Remove trailing newline */
-		if (len > 0 && buf[len - 1] == '\n')
-		{
+		/* Remove trailing newline, including \r in case we're on Windows */
+		while (len > 0 && (buf[len - 1] == '\n' ||
+						   buf[len - 1] == '\r'))
 			buf[--len] = '\0';
-			/* Handle DOS-style line endings, too, even when not on Windows */
-			if (len > 0 && buf[len - 1] == '\r')
-				buf[--len] = '\0';
-		}
 
 		if (len == 0)
 			continue;

src/port/sprompt.c

@@ -144,9 +144,11 @@ simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)
 		} while (buflen > 0 && buf[buflen - 1] != '\n');
 	}
 
-	if (length > 0 && destination[length - 1] == '\n')
-		/* remove trailing newline */
-		destination[length - 1] = '\0';
+	/* strip trailing newline, including \r in case we're on Windows */
+	while (length > 0 &&
+		   (destination[length - 1] == '\n' ||
+			destination[length - 1] == '\r'))
+		destination[--length] = '\0';
 
 	if (!echo)
 	{