test: accept "==" as a synonym for "="

Make GNU coreutils' test recognize "==" as a synonym for "=".
This is already the case in GNU coreutils' expr, bash, ksh,
busybox ash, FreeBSD-current /bin/sh and /bin/test, and
OpenBSD's /bin/sh.

Before, env test a '==' a would fail with this diagnostic:
"test: ==: binary operator expected".  Now, it succeeds.
* src/test.c: Accept "==" as a synonym for "=".
* doc/coreutils.texi (String tests): Document it.
Reported as http://debbugs.gnu.org/8263
Also see http://austingroupbugs.net/view.php?id=375

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 8dd1ed8..46deeed 100644 (file)
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -11535,7 +11535,7 @@ Exit status:
 * File type tests::             -[bcdfhLpSt]
 * Access permission tests::     -[gkruwxOG]
 * File characteristic tests::   -e -s -nt -ot -ef
-* String tests::                -z -n = !=
+* String tests::                -z -n = == !=
 * Numeric tests::               -eq -ne -lt -le -gt -ge
 * Connectives for test::        ! -a -o
 @end menu
@@ -11726,6 +11726,11 @@ True if the length of @var{string} is nonzero.
 @cindex equal string check
 True if the strings are equal.
 
+@item @var{string1} == @var{string2}
+@opindex ==
+@cindex equal string check
+True if the strings are equal (synonym for =).
+
 @item @var{string1} != @var{string2}
 @opindex !=
 @cindex not-equal string check

diff --git a/src/test.c b/src/test.c
index 2d7aa67..362df65 100644 (file)
--- a/src/test.c
+++ b/src/test.c
@@ -173,7 +173,8 @@ get_mtime (char const *filename, struct timespec *mtime)
 static bool
 binop (char const *s)
 {
-  return ((STREQ (s,   "=")) || (STREQ (s,  "!=")) || (STREQ (s, "-nt")) ||
+  return ((STREQ (s,   "=")) || (STREQ (s,  "!=")) || (STREQ (s, "==")) ||
+          (STREQ (s,   "-nt")) ||
           (STREQ (s, "-ot")) || (STREQ (s, "-ef")) || (STREQ (s, "-eq")) ||
           (STREQ (s, "-ne")) || (STREQ (s, "-lt")) || (STREQ (s, "-le")) ||
           (STREQ (s, "-gt")) || (STREQ (s, "-ge")));
@@ -360,7 +361,8 @@ binary_operator (bool l_is_l)
       test_syntax_error (_("unknown binary operator"), argv[op]);
     }
 
-  if (argv[op][0] == '=' && !argv[op][1])
+  if (argv[op][0] == '=' && (!argv[op][1] ||
+       ((argv[op][1] == '=') && !argv[op][2])))
     {
       bool value = STREQ (argv[pos], argv[pos + 2]);
       pos += 3;