From cbdfe0eefbd2707401f542e3e5a4e08c7202a77c Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Tue, 16 Jan 2024 12:02:21 +0100
Subject: [PATCH v2] Make initdb -c option case insensitive

When a -c option specifies a GUC name to replace using different
case than the existing parameter it was added as a new parameter
rather than replacing the existing.  This makes -c replacements
case insensitive such that -cWORK_MEM will update the value of
work_mem in the config.

Reported-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20230928.164904.2153358973162534034.horikyota.ntt@gmail.com
---
 src/bin/initdb/initdb.c        | 46 ++++++++++++++++++++++------------
 src/bin/initdb/t/001_initdb.pl | 12 +++++++++
 2 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index ac409b0006..aa858ece8a 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -471,20 +471,14 @@ replace_guc_value(char **lines, const char *guc_name, const char *guc_value,
 	int			namelen = strlen(guc_name);
 	PQExpBuffer newline = createPQExpBuffer();
 	int			i;
+	const char *where;
+	const char *pname;
 
-	/* prepare the replacement line, except for possible comment and newline */
 	if (mark_as_comment)
 		appendPQExpBufferChar(newline, '#');
-	appendPQExpBuffer(newline, "%s = ", guc_name);
-	if (guc_value_requires_quotes(guc_value))
-		appendPQExpBuffer(newline, "'%s'", escape_quotes(guc_value));
-	else
-		appendPQExpBufferStr(newline, guc_value);
 
 	for (i = 0; lines[i]; i++)
 	{
-		const char *where;
-
 		/*
 		 * Look for a line assigning to guc_name.  Typically it will be
 		 * preceded by '#', but that might not be the case if a -c switch
@@ -494,15 +488,32 @@ replace_guc_value(char **lines, const char *guc_name, const char *guc_value,
 		where = lines[i];
 		while (*where == '#' || isspace((unsigned char) *where))
 			where++;
-		if (strncmp(where, guc_name, namelen) != 0)
+		if (strncasecmp(where, guc_name, namelen) != 0)
 			continue;
+
+		pname = where;
 		where += namelen;
 		while (isspace((unsigned char) *where))
 			where++;
-		if (*where != '=')
-			continue;
 
-		/* found it -- append the original comment if any */
+		/* assume there's only one match */
+		if (*where == '=')
+			break;
+	}
+
+	if (lines[i])
+	{
+		/* Found it, rewrite the line preserving the original comment if any */
+		appendPQExpBuffer(newline, "%.*s = ", namelen, pname);
+		if (guc_value_requires_quotes(guc_value))
+			appendPQExpBuffer(newline, "'%s'", escape_quotes(guc_value));
+		else
+			appendPQExpBufferStr(newline, guc_value);
+
+		/*
+		 * Body of line has been completed, now continue with potential
+		 * indentation and comment.
+		 */
 		where = strrchr(where, '#');
 		if (where)
 		{
@@ -549,16 +560,19 @@ replace_guc_value(char **lines, const char *guc_name, const char *guc_value,
 
 		free(lines[i]);
 		lines[i] = newline->data;
-
-		break;					/* assume there's only one match */
 	}
-
-	if (lines[i] == NULL)
+	else
 	{
 		/*
 		 * No match, so append a new entry.  (We rely on the bootstrap server
 		 * to complain if it's not a valid GUC name.)
 		 */
+		appendPQExpBuffer(newline, "%s = ", guc_name);
+		if (guc_value_requires_quotes(guc_value))
+			appendPQExpBuffer(newline, "'%s'", escape_quotes(guc_value));
+		else
+			appendPQExpBufferStr(newline, guc_value);
+
 		appendPQExpBufferChar(newline, '\n');
 		lines = pg_realloc_array(lines, char *, i + 2);
 		lines[i++] = newline->data;
diff --git a/src/bin/initdb/t/001_initdb.pl b/src/bin/initdb/t/001_initdb.pl
index 03376cc0f7..1c048bba8e 100644
--- a/src/bin/initdb/t/001_initdb.pl
+++ b/src/bin/initdb/t/001_initdb.pl
@@ -199,4 +199,16 @@ command_fails(
 command_fails([ 'initdb', '--no-sync', '--set', 'foo=bar', "$tempdir/dataX" ],
 	'fails for invalid --set option');
 
+# Make sure multiple invocations of -c parameters are added case insensitive
+command_ok(
+	[
+		'initdb', '-cwork_mem=128', '-cWork_Mem=256', '-cWORK_MEM=512',
+		"$tempdir/dataX"
+	],
+	'multiple -c options with different case');
+
+my $conf = slurp_file("$tempdir/dataX/postgresql.conf");
+ok($conf =~ qr/^work_mem = 512/m, "work_mem configured");
+ok($conf !~ qr/^WORK_MEM = 512/m, "WORK_MEM should not be in config");
+
 done_testing();
-- 
2.32.1 (Apple Git-133)