Noticed while investigating a migration to utf-8 strings. After making
changes that routed non-ascii symbol hashing through this function,
encoding-iso88597.test began intermittently failing because it would
traverse trailing garbage when u8_strnlen reported 8 chars instead of 4.
Change the scm_i_str2symbol internal hash type to unsigned long to
explicitly match the hashing result type.
---
Proposed for at least main.
libguile/hash.c | 2 +-
libguile/symbols.c | 2 +-
test-suite/standalone/Makefile.am | 7 ++++
test-suite/standalone/test-hashing.c | 61 ++++++++++++++++++++++++++++
4 files changed, 70 insertions(+), 2 deletions(-)
create mode 100644 test-suite/standalone/test-hashing.c
diff --git a/libguile/hash.c b/libguile/hash.c
index 93431102f..0740b2645 100644
--- a/libguile/hash.c
+++ b/libguile/hash.c
@@ -188,7 +188,7 @@ scm_i_utf8_string_hash (const char *str, size_t len)
/* Invalid UTF-8; punt. */
return scm_i_string_hash (scm_from_utf8_stringn (str, len));
- length = u8_strnlen (ustr, len);
+ length = u8_mbsnlen (ustr, len);
/* Set up the internal state. */
a = b = c = 0xdeadbeef + ((uint32_t)(length<<2)) + 47;
diff --git a/libguile/symbols.c b/libguile/symbols.c
index ad5f22f57..cd9cda3de 100644
--- a/libguile/symbols.c
+++ b/libguile/symbols.c
@@ -239,7 +239,7 @@ static SCM
scm_i_str2symbol (SCM str)
{
SCM symbol;
- size_t raw_hash = scm_i_string_hash (str);
+ unsigned long raw_hash = scm_i_string_hash (str);
symbol = lookup_interned_symbol (str, raw_hash);
if (scm_is_true (symbol))
diff --git a/test-suite/standalone/Makefile.am
b/test-suite/standalone/Makefile.am
index e87100c96..ca1b3131b 100644
--- a/test-suite/standalone/Makefile.am
+++ b/test-suite/standalone/Makefile.am
@@ -167,6 +167,13 @@ test_conversion_LDADD = $(LIBGUILE_LDADD)
$(top_builddir)/lib/libgnu.la
check_PROGRAMS += test-conversion
TESTS += test-conversion
+# test-hashing
+test_hashing_SOURCES = test-hashing.c
+test_hashing_CFLAGS = ${test_cflags}
+test_hashing_LDADD = $(LIBGUILE_LDADD) $(top_builddir)/lib/libgnu.la
+check_PROGRAMS += test-hashing
+TESTS += test-hashing
+
# test-loose-ends
test_loose_ends_SOURCES = test-loose-ends.c
test_loose_ends_CFLAGS = ${test_cflags}
diff --git a/test-suite/standalone/test-hashing.c
b/test-suite/standalone/test-hashing.c
new file mode 100644
index 000000000..476181fe2
--- /dev/null
+++ b/test-suite/standalone/test-hashing.c
@@ -0,0 +1,61 @@
+/* Copyright 2022
+ Free Software Foundation, Inc.
+
+ This file is part of Guile.
+
+ Guile is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Guile is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with Guile. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <libguile.h>
+
+#include <stdio.h>
+
+static void
+test_hashing ()
+{
+ // Make sure a utf-8 symbol has the expected hash. In addition to
+ // catching algorithmic regressions, this would have caught a
+ // long-standing buffer overflow.
+
+ // περί
+ char about_u8[] = {0xce, 0xa0, 0xce, 0xb5, 0xcf, 0x81, 0xce, 0xaf, 0};
+ SCM sym = scm_from_utf8_symbol (about_u8);
+
+ const unsigned long expect = 4029223418961680680;
+ const unsigned long actual = scm_to_ulong (scm_symbol_hash (sym));
+
+ if (actual != expect)
+ {
+ fprintf (stderr, "fail: unexpected utf-8 symbol hash (%lu != %lu)\n",
+ actual, expect);
+ exit (EXIT_FAILURE);
+ }
+}
+
+static void
+tests (void *data, int argc, char **argv)
+{
+ test_hashing ();
+}
+
+int
+main (int argc, char *argv[])
+{
+ scm_boot_guile (argc, argv, tests, NULL);
+ return 0;
+}
--
2.30.2
