Implement a Key/Value environment.

K/V is a new type of environment where variable names (keys) and
values are stored separately in adjacent environment elements.
This should simplify wordsplit initialization in many cases.

* include/mailutils/wordsplit.h (MU_WRDSF_ENV_KV): New flag.
* libmailutils/string/wordsplit.c (mu_wordsplit_find_env): Implement
search in a K/V environment.
* libmailutils/tests/wordsplit.at: Test K/V environments.
* libmailutils/tests/wsp.c (bool_keytab): Implement env_kv.
(make_env_kv): New function.
(main): Convert environment if env_kv is given.

@@ -106,6 +106,9 @@ struct mu_wordsplit
 
 /* ws_closure is set */
 #define MU_WRDSF_CLOSURE           0x2000000
+/* ws_env is a Key/Value environment, i.e. the value of a variable is
+   stored in the element that follows its name. */
+#define MU_WRDSF_ENV_KV            0x4000000
 
 #define MU_WRDSF_DEFFLAGS	       \
   (MU_WRDSF_NOVAR | MU_WRDSF_NOCMD | \

@@ -651,16 +651,35 @@ mu_wordsplit_find_env (struct mu_wordsplit *wsp, const char *name, size_t len)
 
   if (!(wsp->ws_flags & MU_WRDSF_ENV))
     return NULL;
-  for (i = 0; wsp->ws_env[i]; i++)
-    {
-      size_t j;
-      const char *var = wsp->ws_env[i];
 
-      for (j = 0; j < len; j++)
-	if (name[j] != var[j])
-	  break;
-      if (j == len && var[j] == '=')
-	return var + j + 1;
+  if (wsp->ws_flags & MU_WRDSF_ENV_KV)
+    {
+      /* A key-value pair environment */
+      for (i = 0; wsp->ws_env[i]; i++)
+	{
+	  size_t elen = strlen (wsp->ws_env[i]);
+	  if (elen == len && memcmp (wsp->ws_env[i], name, elen) == 0)
+	    return wsp->ws_env[i + 1];
+	  /* Skip the value.  Break the loop if it is NULL. */
+	  i++;
+	  if (wsp->ws_env[i] == NULL)
+	    break;
+	}
+    }
+  else
+    {
+      /* Usual (A=B) environment. */
+      for (i = 0; wsp->ws_env[i]; i++)
+	{
+	  size_t j;
+	  const char *var = wsp->ws_env[i];
+	  
+	  for (j = 0; j < len; j++)
+	    if (name[j] != var[j])
+	      break;
+	  if (j == len && var[j] == '=')
+	    return var + j + 1;
+	}
     }
   return NULL;
 }

@@ -203,6 +203,16 @@ TESTWSP([disable variable expansion],[],[novar],
 [],
 [FOO=bar])
 
+TESTWSP([K/V environment],[],[env_kv],
+[$FOO a$BAZ],
+[NF: 2
+0: bar
+1: aqux
+],
+[],
+[FOO=bar BAZ=qux])
+
+
 TESTWSP([nosplit with expansion],[],[nosplit],
 [a $FOO test],
 [NF: 1

@@ -44,6 +44,7 @@ struct mu_kwd bool_keytab[] = {
   { "warnundef", MU_WRDSF_WARNUNDEF },
   { "cescapes", MU_WRDSF_CESCAPES },
   { "default", MU_WRDSF_DEFFLAGS },
+  { "env_kv", MU_WRDSF_ENV_KV },
   { NULL, 0 }
 };
 
@@ -112,6 +113,49 @@ print_qword (const char *word, int plaintext)
     printf ("%s", qbuf);
 }
 
+/* Convert environment to K/V form */
+static char **
+make_env_kv ()
+{
+  size_t i, j, size;
+  char **newenv;
+  
+  /* Count the number of entries */
+  for (i = 0; environ[i]; i++)
+    ;
+
+  size = (i - 1) * 2 + 1;
+  newenv = calloc (size, sizeof (newenv[0]));
+  if (!newenv)
+    {
+      mu_error ("not enough memory");
+      exit (1);
+    }
+
+  for (i = j = 0; environ[i]; i++)
+    {
+      size_t len = strcspn (environ[i], "=");
+      char *p = malloc (len+1);
+      if (!p)
+	{
+	  mu_error ("not enough memory");
+	  exit (1);
+	}
+      memcpy (p, environ[i], len);
+      p[len] = 0;
+      newenv[j++] = p;
+      p = strdup (environ[i] + len + 1);
+      if (!p)
+	{
+	  mu_error ("not enough memory");
+	  exit (1);
+	}
+      newenv[j++] = p;
+    }
+  newenv[j] = NULL;
+  return newenv;
+}
+    
 int
 main (int argc, char **argv)
 {
@@ -161,7 +205,7 @@ main (int argc, char **argv)
 	  plaintext_option = !negate;
 	  continue;
 	}
-
+	  
       if (mu_kwd_xlat_name (bool_keytab, opt, &flag) == 0)
 	{
 	  if (negate)
@@ -239,7 +283,10 @@ main (int argc, char **argv)
       exit (1);
     }
 
-  ws.ws_env = (const char **) environ;
+  if (wsflags & MU_WRDSF_ENV_KV)
+    ws.ws_env = (const char **) make_env_kv ();
+  else
+    ws.ws_env = (const char **) environ;
 	
   while (fgets (buf, sizeof (buf), stdin))
     {