Fix crash in case of empty # output

CHANGELOG.md

@@ -8,6 +8,8 @@
 
 ## 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`
@@ -733,6 +735,7 @@
 [github-1493]: https://github.com/JuliaDocs/Documenter.jl/pull/1493
 [github-1497]: https://github.com/JuliaDocs/Documenter.jl/pull/1497
 [github-1503]: https://github.com/JuliaDocs/Documenter.jl/pull/1503
+[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

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])

test/doctests/src/working.md

@@ -52,4 +52,11 @@ Comments at the start:
 # .. should be ignored.
 julia> 2 + 2
 4
-```
+```
+
+Empty output:
+
+```jldoctest
+nothing
+# output
+```