vasnprintf-posix: Fix crash in narrow %lc directive (regr. 2023-03-21).

* lib/vasnprintf.c (VASNPRINTF): Negative results of local_wcrtomb can
now occur; handle them.
* tests/test-vasnprintf-posix.c (test_function): Test %lc directive with
a wint_t argument that is not a valid wide character.
* tests/test-snprintf-posix.h (test_function): Likewise.
* tests/test-sprintf-posix.h (test_function): Likewise.
* tests/test-vasnwprintf-posix.c (test_function): Likewise.
* tests/test-vasprintf-posix.c (test_function): Likewise.

5 files changed, 101 insertions, 0 deletions

diff --git a/tests/test-snprintf-posix.h b/tests/test-snprintf-posix.h
index bfc8b9914e..90fcf61c5a 100644
--- a/tests/test-snprintf-posix.h
+++ b/tests/test-snprintf-posix.h
@@ -3089,6 +3089,24 @@ test_function (int (*my_snprintf) (char *, size_t, const char *, ...))
     ASSERT (memcmp (result, "az 33\0", 5 + 1) == 0);
     ASSERT (retval == 5);
   }
+
+  static wint_t L_invalid = (wchar_t) 0x76543210;
+
+  { /* Invalid wide character.
+       The conversion may succeed or may fail, but it should not abort.  */
+    int retval =
+      my_snprintf (result, sizeof (result),
+                   "%lc %d", L_invalid, 33, 44, 55);
+    (void) retval;
+  }
+
+  { /* Invalid wide character and width.
+       The conversion may succeed or may fail, but it should not abort.  */
+    int retval =
+      my_snprintf (result, sizeof (result),
+                   "%10lc %d", L_invalid, 33, 44, 55);
+    (void) retval;
+  }
 #endif
 
   /* Test the support of the 'x' conversion specifier for hexadecimal output of
diff --git a/tests/test-sprintf-posix.h b/tests/test-sprintf-posix.h
index d2f0e579ea..6ea2052186 100644
--- a/tests/test-sprintf-posix.h
+++ b/tests/test-sprintf-posix.h
@@ -3067,6 +3067,22 @@ test_function (int (*my_sprintf) (char *, const char *, ...))
     ASSERT (memcmp (result, "az 33\0", 5 + 1) == 0);
     ASSERT (retval == 5);
   }
+
+  static wint_t L_invalid = (wchar_t) 0x76543210;
+
+  { /* Invalid wide character.
+       The conversion may succeed or may fail, but it should not abort.  */
+    int retval =
+      my_sprintf (result, "%lc %d", L_invalid, 33, 44, 55);
+    (void) retval;
+  }
+
+  { /* Invalid wide character and width.
+       The conversion may succeed or may fail, but it should not abort.  */
+    int retval =
+      my_sprintf (result, "%10lc %d", L_invalid, 33, 44, 55);
+    (void) retval;
+  }
 #endif
 
   /* Test the support of the 'x' conversion specifier for hexadecimal output of
diff --git a/tests/test-vasnprintf-posix.c b/tests/test-vasnprintf-posix.c
index bc71e02156..9eb042c552 100644
--- a/tests/test-vasnprintf-posix.c
+++ b/tests/test-vasnprintf-posix.c
@@ -4015,6 +4015,24 @@ test_function (char * (*my_asnprintf) (char *, size_t *, const char *, ...))
     ASSERT (length == 5);
     free (result);
   }
+
+  static wint_t L_invalid = (wchar_t) 0x76543210;
+
+  { /* Invalid wide character.
+       The conversion may succeed or may fail, but it should not abort.  */
+    size_t length;
+    char *result =
+      my_asnprintf (NULL, &length, "%lc %d", L_invalid, 33, 44, 55);
+    free (result);
+  }
+
+  { /* Invalid wide character and width.
+       The conversion may succeed or may fail, but it should not abort.  */
+    size_t length;
+    char *result =
+      my_asnprintf (NULL, &length, "%10lc %d", L_invalid, 33, 44, 55);
+    free (result);
+  }
 #endif
 
   /* Test the support of the 'x' conversion specifier for hexadecimal output of
diff --git a/tests/test-vasnwprintf-posix.c b/tests/test-vasnwprintf-posix.c
index f0ecfb082a..74a26079d3 100644
--- a/tests/test-vasnwprintf-posix.c
+++ b/tests/test-vasnwprintf-posix.c
@@ -4020,6 +4020,35 @@ test_function (wchar_t * (*my_asnwprintf) (wchar_t *, size_t *, const wchar_t *,
     ASSERT (length == 6);
     free (result);
   }
+
+  static wint_t L_invalid = (wchar_t) 0x76543210;
+
+  { /* Invalid wide character.  */
+    size_t length;
+    wchar_t *result =
+      my_asnwprintf (NULL, &length, L"%lc %d", L_invalid, 33, 44, 55);
+    /* No failure is allowed: ISO C says "the wint_t argument is converted
+       to wchar_t and written."  */
+    ASSERT (result != NULL);
+    ASSERT (result[0] == (wchar_t) 0x76543210);
+    ASSERT (wmemcmp (result + 1, L" 33\0", 3 + 1) == 0);
+    ASSERT (length == 4);
+    free (result);
+  }
+
+  { /* Invalid wide character and width.  */
+    size_t length;
+    wchar_t *result =
+      my_asnwprintf (NULL, &length, L"%10lc %d", L_invalid, 33, 44, 55);
+    /* No failure is allowed: ISO C says "the wint_t argument is converted
+       to wchar_t and written."  */
+    ASSERT (result != NULL);
+    ASSERT (wmemcmp (result, L"         ", 9) == 0);
+    ASSERT (result[9] == (wchar_t) 0x76543210);
+    ASSERT (wmemcmp (result + 10, L" 33\0", 3 + 1) == 0);
+    ASSERT (length == 13);
+    free (result);
+  }
 #endif
 
   /* Test the support of the 'x' conversion specifier for hexadecimal output of
diff --git a/tests/test-vasprintf-posix.c b/tests/test-vasprintf-posix.c
index 6a18413abb..e4cc0fb983 100644
--- a/tests/test-vasprintf-posix.c
+++ b/tests/test-vasprintf-posix.c
@@ -3954,6 +3954,26 @@ test_function (int (*my_asprintf) (char **, const char *, ...))
     ASSERT (retval == 5);
     free (result);
   }
+
+  static wint_t L_invalid = (wchar_t) 0x76543210;
+
+  { /* Invalid wide character.
+       The conversion may succeed or may fail, but it should not abort.  */
+    char *result;
+    int retval =
+      my_asprintf (&result, "%lc %d", L_invalid, 33, 44, 55);
+    if (retval >= 0)
+      free (result);
+  }
+
+  { /* Invalid wide character and width.
+       The conversion may succeed or may fail, but it should not abort.  */
+    char *result;
+    int retval =
+      my_asprintf (&result, "%10lc %d", L_invalid, 33, 44, 55);
+    if (retval >= 0)
+      free (result);
+  }
 #endif
 
   /* Test the support of the 'x' conversion specifier for hexadecimal output of