unigbrk tests: Tweak error reporting

[Bruno Haible]

Failing unigbrk tests showed some Unicode code points as 3-hex-digit numbers.
Which is a bit confusing. By convention, at least 4 hex digits should be shown.


2024-01-30  Bruno Haible  <bruno@clisp.org>

        unigbrk tests: Tweak error reporting.
        * tests/unigbrk/test-ulc-grapheme-breaks.c (main): Print byte values in
        upper-case hexadecimal.
        * tests/unigbrk/test-u8-grapheme-breaks.c (test_u8_grapheme_breaks):
        Print unit values in upper-case hexadecimal.
        * tests/unigbrk/test-u16-grapheme-breaks.c (test_u16_grapheme_breaks):
        Print unit values with at least 4 hexadecimal digits.
        * tests/unigbrk/test-u32-grapheme-breaks.c (test_u32_grapheme_breaks):
        Likewise.
        * tests/unigbrk/test-uc-grapheme-breaks.c (test_uc_grapheme_breaks):
        Print characters with at least 4 hexadecimal digits.

diff --git a/tests/unigbrk/test-u16-grapheme-breaks.c 
b/tests/unigbrk/test-u16-grapheme-breaks.c
index 6ebfebe96f..7936050841 100644
--- a/tests/unigbrk/test-u16-grapheme-breaks.c
+++ b/tests/unigbrk/test-u16-grapheme-breaks.c
@@ -61,17 +61,17 @@ test_u16_grapheme_breaks (const char *expected, ...)
 
         fprintf (stderr, "   input:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, " %02x", s[j]);
+          fprintf (stderr, " %04X", s[j]);
         putc ('\n', stderr);
 
         fprintf (stderr, "expected:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, "  %d", expected[j] == '#');
+          fprintf (stderr, "    %d", expected[j] == '#');
         putc ('\n', stderr);
 
         fprintf (stderr, "  actual:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, "  %d", breaks[j]);
+          fprintf (stderr, "    %d", breaks[j]);
         putc ('\n', stderr);
 
         fflush (stderr);
diff --git a/tests/unigbrk/test-u32-grapheme-breaks.c 
b/tests/unigbrk/test-u32-grapheme-breaks.c
index c041b69287..996555cc23 100644
--- a/tests/unigbrk/test-u32-grapheme-breaks.c
+++ b/tests/unigbrk/test-u32-grapheme-breaks.c
@@ -61,17 +61,17 @@ test_u32_grapheme_breaks (const char *expected, ...)
 
         fprintf (stderr, "   input:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, " %02x", s[j]);
+          fprintf (stderr, " %04X", s[j]);
         putc ('\n', stderr);
 
         fprintf (stderr, "expected:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, "  %d", expected[j] == '#');
+          fprintf (stderr, "    %d", expected[j] == '#');
         putc ('\n', stderr);
 
         fprintf (stderr, "  actual:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, "  %d", breaks[j]);
+          fprintf (stderr, "    %d", breaks[j]);
         putc ('\n', stderr);
 
         fflush (stderr);
diff --git a/tests/unigbrk/test-u8-grapheme-breaks.c 
b/tests/unigbrk/test-u8-grapheme-breaks.c
index 464c02c026..1ccdd60169 100644
--- a/tests/unigbrk/test-u8-grapheme-breaks.c
+++ b/tests/unigbrk/test-u8-grapheme-breaks.c
@@ -50,7 +50,7 @@ test_u8_grapheme_breaks (const char *input, const char 
*expected)
 
         fprintf (stderr, "   input:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, " %02x", s[j]);
+          fprintf (stderr, " %02X", s[j]);
         putc ('\n', stderr);
 
         fprintf (stderr, "expected:");
diff --git a/tests/unigbrk/test-uc-grapheme-breaks.c 
b/tests/unigbrk/test-uc-grapheme-breaks.c
index 966fb96c64..afaab06b25 100644
--- a/tests/unigbrk/test-uc-grapheme-breaks.c
+++ b/tests/unigbrk/test-uc-grapheme-breaks.c
@@ -75,17 +75,17 @@ test_uc_grapheme_breaks (const char *expected, ucs4_t *s, 
size_t n,
 
         fprintf (stderr, "   input:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, " %02x", s[j]);
+          fprintf (stderr, " %04X", s[j]);
         putc ('\n', stderr);
 
         fprintf (stderr, "expected:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, "  %d", expected[j] == '#');
+          fprintf (stderr, "    %d", expected[j] == '#');
         putc ('\n', stderr);
 
         fprintf (stderr, "  actual:");
         for (j = 0; j < n; j++)
-          fprintf (stderr, "  %d", breaks[j]);
+          fprintf (stderr, "    %d", breaks[j]);
         putc ('\n', stderr);
 
         fflush (stderr);
diff --git a/tests/unigbrk/test-ulc-grapheme-breaks.c 
b/tests/unigbrk/test-ulc-grapheme-breaks.c
index 3a817b1fc2..519be6fe10 100644
--- a/tests/unigbrk/test-ulc-grapheme-breaks.c
+++ b/tests/unigbrk/test-ulc-grapheme-breaks.c
@@ -64,7 +64,7 @@ main ()
 
           fprintf (stderr, "   input:");
           for (j = 0; j < LENGTH; j++)
-            fprintf (stderr, " %02x", (unsigned char) s[j]);
+            fprintf (stderr, " %02X", (unsigned char) s[j]);
           putc ('\n', stderr);
 
           fprintf (stderr, "expected:");