From 3c7fd698b0a0e90a1e3975cfe734c71046d38385 Mon Sep 17 00:00:00 2001
From: Fredrik Ekre <ekrefredrik@gmail.com>
Date: Tue, 27 Jul 2021 00:00:27 +0200
Subject: [PATCH] Fix assertion with trailing comment in at-code blocks, fixes
 #1655.

---
 CHANGELOG.md               |  5 +++++
 src/Utilities/Utilities.jl |  2 +-
 test/utilities.jl          | 40 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a2f713f47b..528654d5b60 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Documenter.jl changelog
 
+## Version `v0.27.5`
+
+* ![Bugfix][badge-bugfix] Fix an error introduced in version `v0.27.4` (PR[#1634][github-1634]) which was triggered by trailing comments in `@eval`/`@repl`/`@example` blocks. ([#1655](github-1655), [#](github-))
+
 ## Version `v0.27.4`
 
 * ![Feature][badge-feature] `@example`- and `@repl`-blocks now support colored output by mapping ANSI escape sequences to HTML. This requires Julia >= 1.6 and passing `ansicolor=true` to `Documenter.HTML` (e.g. `makedocs(format=Documenter.HTML(ansicolor=true, ...), ...)`). In Documenter 0.28.0 this will be the default so to (preemptively) opt-out pass `ansicolor=false`. ([#1441][github-1441], [#1628][github-1628], [#1629][github-1629], [#1647][github-1647])
@@ -888,6 +892,7 @@
 [github-1645]: https://github.com/JuliaDocs/Documenter.jl/pull/1645
 [github-1647]: https://github.com/JuliaDocs/Documenter.jl/pull/1647
 [github-1649]: https://github.com/JuliaDocs/Documenter.jl/pull/1649
+[github-1655]: https://github.com/JuliaDocs/Documenter.jl/issues/1655
 
 [julia-38079]: https://github.com/JuliaLang/julia/issues/38079
 [julia-39841]: https://github.com/JuliaLang/julia/pull/39841
diff --git a/src/Utilities/Utilities.jl b/src/Utilities/Utilities.jl
index 8a4aa175fd3..00d321fac97 100644
--- a/src/Utilities/Utilities.jl
+++ b/src/Utilities/Utilities.jl
@@ -118,7 +118,7 @@ function parseblock(code::AbstractString, doc, file; skip = 0, keywords = true,
                 end
             end
         str = SubString(code, cursor, prevind(code, ncursor))
-        if !isempty(strip(str))
+        if !isempty(strip(str)) && ex !== nothing
             push!(results, (ex, str))
         end
         cursor = ncursor
diff --git a/test/utilities.jl b/test/utilities.jl
index 8bc17ca58e4..ad2b4978c58 100644
--- a/test/utilities.jl
+++ b/test/utilities.jl
@@ -299,6 +299,46 @@ end
         end
     end
 
+    @testset "PR #1634, issue #1655" begin
+        let parse(x) = Documenter.Utilities.parseblock(x, nothing, nothing;
+                           linenumbernode=LineNumberNode(123, "testfile.jl")
+                       )
+            code = """
+            1 + 1
+            2 + 2
+            """
+            exs = parse(code)
+            @test length(exs) == 2
+            @test exs[1][2] == "1 + 1\n"
+            @test exs[1][1].head == :toplevel
+            @test exs[1][1].args[1] == LineNumberNode(124, "testfile.jl")
+            @test exs[1][1].args[2] == Expr(:call, :+, 1, 1)
+            @test exs[2][2] == "2 + 2\n"
+            @test exs[2][1].head == :toplevel
+            @test exs[2][1].args[1] == LineNumberNode(125, "testfile.jl")
+            @test exs[2][1].args[2] == Expr(:call, :+, 2, 2)
+
+            # corner case trailing whitespace
+            code1 = """
+            1 + 1
+
+            """
+            # corner case: trailing comment
+            code2 = """
+            1 + 1
+            # comment
+            """
+            for code in (code1, code2)
+                exs = parse(code)
+                @test length(exs) == 1
+                @test exs[1][2] == "1 + 1\n"
+                @test exs[1][1].head == :toplevel
+                @test exs[1][1].args[1] == LineNumberNode(124, "testfile.jl")
+                @test exs[1][1].args[2] == Expr(:call, :+, 1, 1)
+            end
+        end
+    end
+
     @testset "mdparse" begin
         mdparse = Documenter.Utilities.mdparse