Interpret a dbName param to PQsetdbLogin as a conninfo string if it contains...

Interpret a dbName param to PQsetdbLogin as a conninfo string if it contains an = sign. Tom Lane and Andrew Dunstan.

doc/src/sgml/libpq.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.220 2006/11/10 22:15:26 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.221 2006/12/19 01:53:36 adunstan Exp $ -->
 
  <chapter id="libpq">
   <title><application>libpq</application> - C Library</title>
@@ -324,14 +324,20 @@ PGconn *PQsetdbLogin(const char *pghost,
                      const char *login,
                      const char *pwd);
 </synopsis>
-</para>
+    </para>
 
-<para>
+    <para>
      This is the predecessor of <function>PQconnectdb</function> with a fixed
      set of parameters.  It has the same functionality except that the
      missing parameters will always take on default values.  Write <symbol>NULL</symbol> or an
      empty string for any one of the fixed parameters that is to be defaulted.
    </para>
+   <para>
+     If the <parameter>dbName</parameter> contains an <symbol>=</symbol> sign, it
+	 is taken as a <parameter>conninfo</parameter> string in exactly the same way as
+	 if it had been passed to <function>PQconnectdb</function>, and the remaining
+	 parameters are then applied as above.
+   </para>
   </listitem>
  </varlistentry>
 

doc/src/sgml/ref/psql-ref.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.178 2006/12/06 15:47:22 momjian Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/psql-ref.sgml,v 1.179 2006/12/19 01:53:36 adunstan Exp $
 PostgreSQL documentation
 -->
 
@@ -112,6 +112,10 @@ PostgreSQL documentation
       equivalent to specifying <replaceable
       class="parameter">dbname</replaceable> as the first non-option
       argument on the command line.
+      </para>
+	  <para>
+	  If this parameter contains an <symbol>=</symbol> sign, it it treated as a
+	  <parameter>conninfo</parameter> string. See <xref linkend="libpq-connect"> for more information.
 	  </para>
       </listitem>
     </varlistentry>
@@ -556,6 +560,18 @@ PostgreSQL documentation
     </para>
 
 	<para>
+    An alternative way to specify connection parameters is in a
+	<parameter>conninfo</parameter>	string, which is used instead of a 
+	database name. This mechanism give you very wide control over the 
+	connection. For example,
+<programlisting>
+$ <userinput>psql "service=myservice sslmode=require"</userinput>
+</programlisting>
+    See <xref linkend="libpq-connect"> for more information on all the
+	available connection options.
+	</para>
+
+    <para>
     If the connection could not be made for any reason (e.g., insufficient
     privileges, server is not running on the targeted host, etc.),
     <application>psql</application> will return an error and terminate.

src/interfaces/libpq/fe-connect.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.339 2006/11/21 16:28:00 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.340 2006/12/19 01:53:36 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -574,16 +574,36 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 	conn = makeEmptyPGconn();
 	if (conn == NULL)
 		return NULL;
-
     /*
-	 * Parse an empty conninfo string in order to set up the same defaults
-	 * that PQconnectdb() would use.
+     * If the dbName parameter contains '=', assume it's a conninfo
+     * string.
+     */
+    if (dbName && strchr(dbName,'='))
+    {
+        if (!connectOptions1(conn, dbName))
+            return conn;
+    }
+    else
+    {
+        /*
+         * Old-style path: first, parse an empty conninfo string in
+         * order to set up the same defaults that PQconnectdb() would use.
          */
         if (!connectOptions1(conn, ""))
             return conn;
 
+        /* Insert dbName parameter value into struct */
+        if (dbName && dbName[0] != '\0')
+        {
+            if (conn->dbName)
+                free(conn->dbName);
+            conn->dbName = strdup(dbName);
+        }
+    }
+
     /*
-	 * Absorb specified options into conn structure, overriding defaults
+     * Insert remaining parameters into struct, overriding defaults
+     * (as well as any conflicting data from dbName taken as a conninfo).
 	 */
 	if (pghost && pghost[0] != '\0')
 	{
@@ -613,13 +633,6 @@ PQsetdbLogin(const char *pghost, const char *pgport, const char *pgoptions,
 		conn->pgtty = strdup(pgtty);
 	}
 
-	if (dbName && dbName[0] != '\0')
-	{
-		if (conn->dbName)
-			free(conn->dbName);
-		conn->dbName = strdup(dbName);
-	}
-
 	if (login && login[0] != '\0')
 	{
 		if (conn->pguser)