Fixes #248: make sure to unlock the binding metadata before updatin…

…g its value
rstudio · Nov 2, 2015 · 72bc5ad · 72bc5ad · mattsigal · Nov 3, 2015
1 parent e4660a3
commit 72bc5ad
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diff --git a/R/render.R b/R/render.R
@@ -299,9 +299,13 @@ render <- function(input,
     # knit environment (unless it is already defined there in which case
     # we emit a warning)
     env <- environment(render)
+    metadata_this <- env$metadata
     do.call("unlockBinding", list("metadata", env))
     on.exit({
-      env$metadata <- list()
+      if (bindingIsLocked("metadata", env)) {
+        do.call("unlockBinding", list("metadata", env))
+      }
+      env$metadata <- metadata_this
       lockBinding("metadata", env)
     }, add = TRUE)
     env$metadata <- yaml_front_matter

diff --git a/inst/NEWS b/inst/NEWS
@@ -19,6 +19,9 @@ rmarkdown 0.8.3 (unreleased)
 
 * Always use the graphics package for PDF output
 
+* Fix for the error "cannot change value of locked binding for 'metadata'" when
+  one call of rmarkdown::render() is nested in another one (#248)
+
 rmarkdown 0.8.1
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