From d352a01adbee816586ed374de9c44bb69edb9848 Mon Sep 17 00:00:00 2001
From: Jeremie Knuesel <knuesel@gmail.com>
Date: Wed, 3 Feb 2021 07:03:57 +0100
Subject: [PATCH] Fix crash in case of empty `# output` (#1510)

(cherry picked from commit dffba5fcdb314b227f65c0164a2f78c68d1d3ece)
---
 CHANGELOG.md                 | 3 +++
 src/DocTests.jl              | 2 +-
 test/doctests/src/working.md | 9 ++++++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d270187201..a46a4f0e63 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Version `v0.26.2`
 
+* ![Bugfix][badge-bugfix] Script-type doctests that have an empty output section no longer crash Documenter. ([#1510][github-1510])
+
 * ![Bugfix][badge-bugfix] When checking for authentication keys when deploying, Documenter now more appropriately checks if the environment variables are non-empty, rather than just whether they are defined. ([#1511][github-1511])
 
 ## Version `v0.26.1`
@@ -726,6 +728,7 @@
 [github-1491]: https://github.com/JuliaDocs/Documenter.jl/pull/1491
 [github-1493]: https://github.com/JuliaDocs/Documenter.jl/pull/1493
 [github-1497]: https://github.com/JuliaDocs/Documenter.jl/pull/1497
+[github-1510]: https://github.com/JuliaDocs/Documenter.jl/pull/1510
 [github-1511]: https://github.com/JuliaDocs/Documenter.jl/pull/1511
 
 [julia-38079]: https://github.com/JuliaLang/julia/issues/38079
diff --git a/src/DocTests.jl b/src/DocTests.jl
index f3b0cea08a..d9d6e82751 100644
--- a/src/DocTests.jl
+++ b/src/DocTests.jl
@@ -239,7 +239,7 @@ function eval_script(block, sandbox, meta::Dict, doc::Documents.Document, page)
     #
     #
     #       to mark `input`/`output` separation.
-    input, output = split(block.code, "# output\n", limit = 2)
+    input, output = split(block.code, r"^# output$"m, limit = 2)
     input  = rstrip(input, '\n')
     output = lstrip(output, '\n')
     result = Result(block, input, output, meta[:CurrentFile])
diff --git a/test/doctests/src/working.md b/test/doctests/src/working.md
index 677180caa4..0f743069da 100644
--- a/test/doctests/src/working.md
+++ b/test/doctests/src/working.md
@@ -52,4 +52,11 @@ Comments at the start:
 # .. should be ignored.
 julia> 2 + 2
 4
-```
\ No newline at end of file
+```
+
+Empty output:
+
+```jldoctest
+nothing
+# output
+```