Re: Unicode normalization test broken output

[Peter Eisentraut]

On 2019-12-09 23:22, Tom Lane wrote:

Peter Eisentraut <peter.eisentr...@2ndquadrant.com> writes:

There appear to be several off-by-more-than-one errors in norm_test.c
print_wchar_str().  Attached is a patch to fix this (and make the output
a bit prettier).  Result afterwards:

I concur that this looks broken and your patch improves it.
But I'm not very happy about the remaining assumption that
we don't have to worry about characters above U+FFFF.  I'd
rather see it allocate 11 bytes per allowed pg_wchar, and
manage the string contents with something like

        p += sprintf(p, "U+%04X ", *s);

Good point.  Fixed in attached patch.

--
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

From bece2b343999f1545f1ff2b5be060d7a0e22a91a Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Tue, 10 Dec 2019 13:17:20 +0100
Subject: [PATCH v2] Fix output of Unicode normalization test

Several off-by-more-than-one errors caused the output in case of a
test failure to be unintelligible.

Discussion: 
https://www.postgresql.org/message-id/flat/6a7a8516-7d11-8fbd-0e8b-eadb4f0679eb%402ndquadrant.com
---
 src/common/unicode/norm_test.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/common/unicode/norm_test.c b/src/common/unicode/norm_test.c
index fee58a184a..de7d6a72c7 100644
--- a/src/common/unicode/norm_test.c
+++ b/src/common/unicode/norm_test.c
@@ -23,17 +23,20 @@ static char *
 print_wchar_str(const pg_wchar *s)
 {
 #define BUF_DIGITS 50
-       static char buf[BUF_DIGITS * 2 + 1];
+       static char buf[BUF_DIGITS * 11 + 1];
        int                     i;
+       char       *p;
 
        i = 0;
+       p = buf;
        while (*s && i < BUF_DIGITS)
        {
-               snprintf(&buf[i * 2], 3, "%04X", *s);
+               p += sprintf(p, "U+%04X ", *s);
                i++;
                s++;
        }
-       buf[i * 2] = '\0';
+       *p = '\0';
+
        return buf;
 }
 
@@ -67,9 +70,9 @@ main(int argc, char **argv)
                if (pg_wcscmp(test->output, result) != 0)
                {
                        printf("FAILURE (NormalizationTest.txt line %d):\n", 
test->linenum);
-                       printf("input:\t%s\n", print_wchar_str(test->input));
-                       printf("expected:\t%s\n", 
print_wchar_str(test->output));
-                       printf("got\t%s\n", print_wchar_str(result));
+                       printf("input:    %s\n", print_wchar_str(test->input));
+                       printf("expected: %s\n", print_wchar_str(test->output));
+                       printf("got:      %s\n", print_wchar_str(result));
                        printf("\n");
                        exit(1);
                }
-- 
2.24.0