Parsed labels breaks (bad anchoring) with phantom-dodging 0-length characters

[yngman]

Summary

In #49 (labels should not overlap unlabeled data points) fixed overlapping issue (for default parsed = FALSE), with 0-length characters denoting phantom labels.

However parsed = TRUE seem to break, causing labels to associate with the wrong data points.

Minimal code example

Code similar to #49, demonstrating expected output and that issue only appears with 0-length characters:

library(ggplot2)
library(dplyr)
library(tidyr)
library(ggrepel)

best <- mpg %>%
    group_by(class) %>%
    filter(hwy == max(hwy)) %>%
    distinct(model, .keep_all = T) %>% 
    mutate(best = model)
data <- mpg %>%
    left_join(best) %>%
    replace_na(list(best = '')) %>%
    mutate(best = gsub(' +', ' ~ ', best)) %>% 
    mutate(best = gsub('(\\d+)', '\\1*', best))

ggplot(data, aes(displ, hwy)) +
    geom_point(aes(colour = class)) +
    geom_label_repel(
        mapping = aes(label = best)
    )

ggplot(data, aes(displ, hwy)) +
    geom_point(aes(colour = class)) +
    geom_label_repel(
        mapping = aes(label = best),
        parse = TRUE
    )

ggplot(data, aes(displ, hwy)) +
    geom_point(aes(colour = class)) +
    geom_label_repel(
        mapping = aes(label = best),
        data = filter(data, nchar(best) > 0),
        parse = TRUE
    )

First plot, showing expected output (via parse = FALSE):

Second plot, showing issues when parse = TRUE:

Third plot, showing that parse = TRUE produces no issues with separate data (no phantom-dodging):

Version information

Here is the output from sessionInfo() in my R session:

> sessionInfo()
R version 3.4.4 (2018-03-15)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.1 LTS

Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.7.1
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.7.1

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=sv_SE.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=sv_SE.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=sv_SE.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=sv_SE.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] tidyr_0.8.1    bindrcpp_0.2.2 ggrepel_0.8.0  dplyr_0.7.7    ggplot2_3.0.0  colorout_1.2-0

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.19     rstudioapi_0.8   bindr_0.1.1      magrittr_1.5     tidyselect_0.2.5 munsell_0.5.0    colorspace_1.3-2
 [8] R6_2.3.0         rlang_0.2.2      fansi_0.4.0      plyr_1.8.4       tools_3.4.4      grid_3.4.4       gtable_0.2.0    
[15] utf8_1.1.4       cli_1.0.1        withr_2.1.2      digest_0.6.18    lazyeval_0.2.1   assertthat_0.2.0 tibble_1.4.2    
[22] crayon_1.3.4     purrr_0.2.5      glue_1.3.0       labeling_0.3     compiler_3.4.4   pillar_1.3.0     scales_1.0.0    
[29] pkgconfig_2.0.2

[slowkow]

Duplicate of #114

[yngman]

Ah, my mistake! Sorry for that.

Tried to find earlier issue, but was probably to focused on the phrasing of #49 to notice #114.