test-ctype: test isascii

Test the character classifier added by c2e9364 (cleanup: add
isascii(), 2009-03-07).  It returns 1 for NUL as well, which requires
special treatment, as our string-based tester can't find it with
strcmp(3).  Allow NUL to be given as the first character in a class
specification string.  This has the downside of no longer supporting
the empty string, but that's OK since we are not interested in testing
character classes with no members.

Signed-off-by: René Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

t/helper/test-ctype.c

@@ -11,9 +11,14 @@ static void report_error(const char *class, int ch)
 
 static int is_in(const char *s, int ch)
 {
-	/* We can't find NUL using strchr.  It's classless anyway. */
+	/*
+	 * We can't find NUL using strchr. Accept it as the first
+	 * character in the spec -- there are no empty classes.
+	 */
 	if (ch == '\0')
-		return 0;
+		return ch == *s;
+	if (*s == '\0')
+		s++;
 	return !!strchr(s, ch);
 }
 
@@ -28,6 +33,15 @@ static int is_in(const char *s, int ch)
 #define DIGIT "0123456789"
 #define LOWER "abcdefghijklmnopqrstuvwxyz"
 #define UPPER "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+#define ASCII \
+	"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" \
+	"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" \
+	"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f" \
+	"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f" \
+	"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f" \
+	"\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f" \
+	"\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f" \
+	"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f"
 
 int cmd__ctype(int argc, const char **argv)
 {
@@ -38,6 +52,7 @@ int cmd__ctype(int argc, const char **argv)
 	TEST_CLASS(is_glob_special, "*?[\\");
 	TEST_CLASS(is_regex_special, "$()*+.?[\\^{|");
 	TEST_CLASS(is_pathspec_magic, "!\"#%&',-/:;<=>@_`~");
+	TEST_CLASS(isascii, ASCII);
 
 	return rc;
 }