0001-Use-stringInfo-instead-of-char-in-replace_string.patch

From 66fdc9b006797592c41de6cc1619f96104260e9d Mon Sep 17 00:00:00 2001
From: Georgios Kokolatos <gkokolatos@protonmail.com>
Date: Fri, 31 Jul 2020 09:10:36 +0000
Subject: [PATCH] Use a stringInfo instead of a char for replace_string in
 pg_regress

The exposed function replase_string() in pg_regress assumes that there exists
enough space in the string it operates on. While this is documented and
expected, the consequence can be subtle failures in the tests which might be
hard to trace back to the root cause.

Provide an alternative function that operates on a StringInfo instead.

Co-authored-by: Asim R P <pasim@vmware.com>
---
 src/test/regress/pg_regress.c | 41 ++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index d82e0189dc..78b5057069 100644
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -33,6 +33,7 @@
 #include "common/restricted_token.h"
 #include "common/username.h"
 #include "getopt_long.h"
+#include "lib/stringinfo.h"
 #include "libpq/pqcomm.h"		/* needed for UNIXSOCK_PATH() */
 #include "pg_config_paths.h"
 #include "pg_regress.h"
@@ -454,6 +455,27 @@ replace_string(char *string, const char *replace, const char *replacement)
 	}
 }
 
+/*
+ * Replace all occurrences of a string in a stringInfo with a different string.
+ */
+static void
+replace_stringInfo(StringInfo string, const char *replace, const char *replacement)
+{
+	char	   *ptr;
+
+	while ((ptr = strstr(string->data, replace)) != NULL)
+	{
+		char	   *dup = pg_strdup(string->data);
+		size_t		pos = ptr - string->data;
+
+		string->len = pos;
+		appendStringInfoString(string, replacement);
+		appendStringInfoString(string, dup + pos + strlen(replace));
+
+		free(dup);
+	}
+}
+
 /*
  * Convert *.source found in the "source" directory, replacing certain tokens
  * in the file contents with their intended values, and put the resulting files
@@ -521,7 +543,7 @@ convert_sourcefiles_in(const char *source_subdir, const char *dest_dir, const ch
 		char		prefix[MAXPGPATH];
 		FILE	   *infile,
 				   *outfile;
-		char		line[1024];
+		StringInfoData	line;
 
 		/* reject filenames not finishing in ".source" */
 		if (strlen(*name) < 8)
@@ -551,15 +573,18 @@ convert_sourcefiles_in(const char *source_subdir, const char *dest_dir, const ch
 					progname, destfile, strerror(errno));
 			exit(2);
 		}
-		while (fgets(line, sizeof(line), infile))
+
+		initStringInfo(&line);
+		while (fgets(line.data, line.maxlen, infile))
 		{
-			replace_string(line, "@abs_srcdir@", inputdir);
-			replace_string(line, "@abs_builddir@", outputdir);
-			replace_string(line, "@testtablespace@", testtablespace);
-			replace_string(line, "@libdir@", dlpath);
-			replace_string(line, "@DLSUFFIX@", DLSUFFIX);
-			fputs(line, outfile);
+			replace_stringInfo(&line, "@abs_srcdir@", inputdir);
+			replace_stringInfo(&line, "@abs_builddir@", outputdir);
+			replace_stringInfo(&line, "@testtablespace@", testtablespace);
+			replace_stringInfo(&line, "@libdir@", dlpath);
+			replace_stringInfo(&line, "@DLSUFFIX@", DLSUFFIX);
+			fputs(line.data, outfile);
 		}
+		pfree(line.data);
 		fclose(infile);
 		fclose(outfile);
 	}
-- 
2.25.1