function read_entry( $f, $lineno = 0 ) {
			$entry = new Translation_Entry();
			// where were we in the last step
			// can be: comment, msgctxt, msgid, msgid_plural, msgstr, msgstr_plural
			$context      = '';
			$msgstr_index = 0;
			while ( true ) {
				$lineno++;
				$line = PO::read_line( $f );
				if ( ! $line ) {
					if ( feof( $f ) ) {
						if ( self::is_final( $context ) ) {
							break;
						} elseif ( ! $context ) { // we haven't read a line and eof came
							return null;
						} else {
							return false;
						}
					} else {
						return false;
					}
				}
				if ( $line == "\n" ) {
					continue;
				}
				$line = trim( $line );
				if ( preg_match( '/^#/', $line, $m ) ) {
					// the comment is the start of a new entry
					if ( self::is_final( $context ) ) {
						PO::read_line( $f, 'put-back' );
						$lineno--;
						break;
					}
					// comments have to be at the beginning
					if ( $context && $context != 'comment' ) {
						return false;
					}
					// add comment
					$this->add_comment_to_entry( $entry, $line );
				} elseif ( preg_match( '/^msgctxt\s+(".*")/', $line, $m ) ) {
					if ( self::is_final( $context ) ) {
						PO::read_line( $f, 'put-back' );
						$lineno--;
						break;
					}
					if ( $context && $context != 'comment' ) {
						return false;
					}
					$context         = 'msgctxt';
					$entry->context .= PO::unpoify( $m[1] );
				} elseif ( preg_match( '/^msgid\s+(".*")/', $line, $m ) ) {
					if ( self::is_final( $context ) ) {
						PO::read_line( $f, 'put-back' );
						$lineno--;
						break;
					}
					if ( $context && $context != 'msgctxt' && $context != 'comment' ) {
						return false;
					}
					$context          = 'msgid';
					$entry->singular .= PO::unpoify( $m[1] );
				} elseif ( preg_match( '/^msgid_plural\s+(".*")/', $line, $m ) ) {
					if ( $context != 'msgid' ) {
						return false;
					}
					$context          = 'msgid_plural';
					$entry->is_plural = true;
					$entry->plural   .= PO::unpoify( $m[1] );
				} elseif ( preg_match( '/^msgstr\s+(".*")/', $line, $m ) ) {
					if ( $context != 'msgid' ) {
						return false;
					}
					$context             = 'msgstr';
					$entry->translations = array( PO::unpoify( $m[1] ) );
				} elseif ( preg_match( '/^msgstr\[(\d+)\]\s+(".*")/', $line, $m ) ) {
					if ( $context != 'msgid_plural' && $context != 'msgstr_plural' ) {
						return false;
					}
					$context                      = 'msgstr_plural';
					$msgstr_index                 = $m[1];
					$entry->translations[ $m[1] ] = PO::unpoify( $m[2] );
				} elseif ( preg_match( '/^".*"$/', $line ) ) {
					$unpoified = PO::unpoify( $line );
					switch ( $context ) {
						case 'msgid':
							$entry->singular .= $unpoified;
							break;
						case 'msgctxt':
							$entry->context .= $unpoified;
							break;
						case 'msgid_plural':
							$entry->plural .= $unpoified;
							break;
						case 'msgstr':
							$entry->translations[0] .= $unpoified;
							break;
						case 'msgstr_plural':
							$entry->translations[ $msgstr_index ] .= $unpoified;
							break;
						default:
							return false;
					}
				} else {
					return false;
				}
			}

			$have_translations = false;
			foreach ( $entry->translations as $t ) {
				if ( $t || ( '0' === $t ) ) {
					$have_translations = true;
					break;
				}
			}
			if ( false === $have_translations ) {
				$entry->translations = array();
			}

			return array(
				'entry'  => $entry,
				'lineno' => $lineno,
			);
		}