Only inherit aesthetics when needed in legend.

Fixes #1267. Can now also set show.legend = NA in rule geoms.

Author: hadley

NEWS

@@ -1,6 +1,8 @@
 ggplot2 1.0.1.9xxx
 ----------------------------------------------------------------
 
+* Legends no longer inherit aesthetics if `inherit.aes` is FALSE (#1267).
+
 * The default themes has been tweaked in various minor ways. The legend
   title and axis titles are now given the same treatment. The default
   font size has been dropped from 12 to 11. The axes labels are now

R/geom-abline.r

@@ -67,7 +67,7 @@ NULL
 #'   geom_point() +
 #'   geom_hline(aes(yintercept = wt, colour = wt), mean_wt) +
 #'   facet_wrap(~ cyl)
-geom_abline <- function(mapping = NULL, data = NULL, show.legend = FALSE, ...,
+geom_abline <- function(mapping = NULL, data = NULL, show.legend = NA, ...,
                         slope, intercept) {
 
   # If nothing set, default to y = x

R/geom-vline.r

@@ -3,7 +3,7 @@ NULL
 
 #' @export
 #' @rdname geom_abline
-geom_vline <- function(mapping = NULL, data = NULL, show.legend = FALSE,
+geom_vline <- function(mapping = NULL, data = NULL, show.legend = NA,
                        xintercept, ...) {
 
   # Act like an annotation

R/guide-legend.r

@@ -238,7 +238,7 @@ guide_merge.legend <- function(guide, new_guide) {
 guide_geom.legend <- function(guide, layers, default_mapping) {
   # arrange common data for vertical and horizontal guide
   guide$geoms <- plyr::llply(layers, function(layer) {
-    all <- names(c(layer$mapping, default_mapping, layer$stat$default_aes))
+    all <- names(c(layer$mapping, if (layer$inherit.aes) default_mapping, layer$stat$default_aes))
     geom <- c(layer$geom$required_aes, names(layer$geom$default_aes))
     matched <- intersect(intersect(all, geom), names(guide$key))
     matched <- setdiff(matched, names(layer$geom_params))

man/geom_abline.Rd

@@ -6,13 +6,12 @@
 \alias{geom_vline}
 \title{Lines: horizontal, vertical, and specified by slope and intercept.}
 \usage{
-geom_abline(mapping = NULL, data = NULL, show.legend = FALSE, ..., slope,
+geom_abline(mapping = NULL, data = NULL, show.legend = NA, ..., slope,
   intercept)
 
 geom_hline(mapping = NULL, data = NULL, show.legend = NA, yintercept, ...)
 
-geom_vline(mapping = NULL, data = NULL, show.legend = FALSE, xintercept,
-  ...)
+geom_vline(mapping = NULL, data = NULL, show.legend = NA, xintercept, ...)
 }
 \arguments{
 \item{mapping}{The aesthetic mapping, usually constructed with