From ca398c2de670bf67741627de51c3ba8f4db12937 Mon Sep 17 00:00:00 2001
From: Christophe Dervieux <christophe.dervieux@gmail.com>
Date: Tue, 17 May 2022 23:22:21 +0200
Subject: [PATCH] fix #2126: check `file` and `code` chunk option when checking
 label duplication (#2127)

Co-authored-by: Yihui Xie <xie@yihui.name>
---
 NEWS.md                    |  2 ++
 R/block.R                  | 27 +++++++++++++++++++--------
 R/parser.R                 |  3 ++-
 tests/testit/test-parser.R | 20 ++++++++++++++++++++
 4 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 38a68280ef..2cdcbb12cd 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -4,6 +4,8 @@
 
 - The internal function `knitr:::wrap()` has been removed from this package. If you rely on this function, you will have to use the exported function `knitr::sew()` instead.
 
+- Duplicate chunk label error will now be thrown with code chunks using `code` or `file` chunk options (thanks, @mine-cetinkaya-rundel, #2126).
+
 # CHANGES IN knitr VERSION 1.39
 
 ## MAJOR CHANGES
diff --git a/R/block.R b/R/block.R
index c68655e683..ba592a9c57 100644
--- a/R/block.R
+++ b/R/block.R
@@ -30,14 +30,7 @@ call_block = function(block) {
     if (inherits(params$ref.label, 'AsIs') && is.null(params$opts.label))
       params$opts.label = ref.label
   }
-  # if chunk option 'file' is provided, read the file(s) as the chunk body;
-  # otherwise if 'code' is provided, use it; if neither 'file' nor 'code' is
-  # provided, use the chunk body
-  params[["code"]] = if (is.null(code_file <- params[['file']])) {
-    params[["code"]] %n% unlist(knit_code$get(ref.label), use.names = FALSE)
-  } else {
-    in_input_dir(xfun::read_all(code_file))
-  }
+  params[['code']] = get_code(params, label, ref.label)
 
   # opts.label = TRUE means inheriting chunk options from ref.label
   if (isTRUE(params$opts.label)) params$opts.label = ref.label
@@ -125,6 +118,24 @@ call_block = function(block) {
   block_exec(params)
 }
 
+# if chunk option 'file' is provided, read the file(s) as the chunk body;
+# otherwise if 'code' is provided, use it; if neither 'file' nor 'code' is
+# provided, use the chunk body
+get_code = function(params, label, ref.label) {
+  if (is.null(code <- params[['code']]) && is.null(file <- params[['file']]))
+    return(unlist(knit_code$get(ref.label), use.names = FALSE))
+  if (!is.null(file)) code = in_input_dir(xfun::read_all(file))
+  set_code(label, code)
+  code
+}
+
+# replace code in knit_code but preserve attributes
+set_code = function(label, code) {
+  res = knit_code$get(label)
+  attributes(code) = attributes(res)
+  knit_code$set(setNames(list(code), label))
+}
+
 # options that should affect cache when cache level = 1,2
 cache1.opts = c('code', 'eval', 'cache', 'cache.path', 'cache.globals', 'message', 'warning', 'error')
 # more options affecting cache level 2
diff --git a/R/parser.R b/R/parser.R
index 083d303f94..b5bfea2852 100644
--- a/R/parser.R
+++ b/R/parser.R
@@ -105,7 +105,7 @@ parse_block = function(code, header, params.src, markdown_mode = out_format('mar
   code = parts$code
 
   label = params$label; .knitEnv$labels = c(.knitEnv$labels, label)
-  if (length(code)) {
+  if (length(code) || length(params$file) || length(params$code)) {
     if (label %in% names(knit_code$get())) {
       if (identical(getOption('knitr.duplicate.label'), 'allow')) {
         params$label = label = unnamed_chunk(label)
@@ -114,6 +114,7 @@ parse_block = function(code, header, params.src, markdown_mode = out_format('mar
         one_string(knit_code$get(label))
       )
     }
+    code = as.character(code)
     knit_code$set(setNames(list(structure(code, chunk_opts = params)), label))
   }
 
diff --git a/tests/testit/test-parser.R b/tests/testit/test-parser.R
index 345d26e218..1033e0a92b 100644
--- a/tests/testit/test-parser.R
+++ b/tests/testit/test-parser.R
@@ -95,3 +95,23 @@ assert(
 )
 
 knit_code$restore()
+
+# duplication of labels
+
+knit_code$restore(list(a = '1+1'))
+
+assert(
+  !has_error(parse_block(NULL, '', 'label = "a"')),
+  has_error(parse_block('2+2', '', 'label = "a"')),
+  has_error(parse_block(NULL, '','label = "a", code = "2+2"')),
+  has_error(parse_block(NULL, '','label = "a", file = "dummy.R"'))
+)
+op = options(knitr.duplicate.label = 'allow')
+assert(
+  !has_error(parse_block('2+2', '', 'label = "a"')),
+  !has_error(parse_block(NULL, '','label = "a", code = "2+2"')),
+  !has_error(parse_block(NULL, '','label = "a", file = "dummy.R"'))
+)
+options(op)
+
+knit_code$restore()