Replace Docs.isexpr with Meta.isexpr

This fixes the bounds error reported in #13467 by removing the custom
`isexpr` function that was defined in the `Docs` module. Instead use the
standard `Meta.isexpr` function.

Fixes #13467.

(cherry picked from commit b53ae9d)
ref #13468

base/docs/Docs.jl

@@ -57,7 +57,7 @@ function.
 include("bindings.jl")
 
 import Base.Markdown: @doc_str, MD
-import Base.Meta: quot
+import Base.Meta: quot, isexpr
 
 export doc
 
@@ -247,7 +247,9 @@ catdoc(xs...) = vcat(xs...)
 
 # Type Documentation
 
-isdoc(x) = isexpr(x, :string, AbstractString) ||
+isdoc(s::AbstractString) = true
+
+isdoc(x) = isexpr(x, :string) ||
     (isexpr(x, :macrocall) && x.args[1] == symbol("@doc_str")) ||
     (isexpr(x, :call) && x.args[1] == Expr(:., Base.Markdown, QuoteNode(:doc_str)))
 
@@ -259,7 +261,7 @@ function field_meta(def)
     for l in def.args[3].args
         if isdoc(l)
             doc = mdify(l)
-        elseif doc !== nothing && isexpr(l, Symbol, :(::))
+        elseif doc !== nothing && (isa(l, Symbol) || isexpr(l, :(::)))
             meta[namify(l)] = doc
             doc = nothing
         end
@@ -358,8 +360,8 @@ function typesummary(T::DataType)
 end
 
 isfield(x) = isexpr(x, :.) &&
-  (isexpr(x.args[1], Symbol) || isfield(x.args[1])) &&
-  isexpr(x.args[2], QuoteNode, :quote)
+  (isa(x.args[1], Symbol) || isfield(x.args[1])) &&
+  (isa(x.args[2], QuoteNode) || isexpr(x.args[2], :quote))
 
 function fielddoc(T, k)
     for mod in modules
@@ -390,11 +392,6 @@ const keywords = Dict{Symbol,Any}()
 
 # Usage macros
 
-isexpr(x::Expr) = true
-isexpr(x) = false
-isexpr(x::Expr, ts...) = x.head in ts
-isexpr(x, ts...) = any(T->isa(T, Type) && isa(x, T), ts)
-
 function unblock(ex)
     isexpr(ex, :block) || return ex
     exs = filter(ex -> !(isa(ex, LineNumberNode) || isexpr(ex, :line)), ex.args)
@@ -409,7 +406,7 @@ namify(ex::QuoteNode) = ex.value
 namify(sy::Symbol) = sy
 
 function mdify(ex)
-    if isexpr(ex, AbstractString, :string)
+    if isa(ex, AbstractString) || isexpr(ex, :string)
         :(Markdown.doc_str($(esc(ex)), @__FILE__, current_module()))
     else
         esc(ex)
@@ -496,7 +493,7 @@ more than one expression is marked then the same docstring is applied to each ex
 :(Base.@__doc__)
 
 function __doc__!(meta, def::Expr)
-    if isexpr(def, :block) && length(def.args) == 2 && def.args[1] == symbol("#doc#")
+    if isexpr(def, :block, 2) && def.args[1] == symbol("#doc#")
         # Convert `Expr(:block, :#doc#, ...)` created by `@__doc__` to an `@doc`.
         def.head = :macrocall
         def.args = [symbol("@doc"), meta, def.args[end]]
@@ -511,7 +508,7 @@ function __doc__!(meta, def::Expr)
 end
 __doc__!(meta, def) = false
 
-fexpr(ex) = isexpr(ex, :function, :stagedfunction, :(=)) && isexpr(ex.args[1], :call)
+fexpr(ex) = isexpr(ex, [:function, :stagedfunction, :(=)]) && isexpr(ex.args[1], :call)
 
 function docm(meta, def, define = true)
 
@@ -539,8 +536,8 @@ function docm(meta, def, define = true)
     isexpr(def′, :bitstype)    ? namedoc(meta, def, namify(def′.args[2])) :
     isexpr(def′, :typealias)   ?  vardoc(meta, def, namify(def′)) :
     isexpr(def′, :module)      ?  moddoc(meta, def, def′.args[2]) :
-    isexpr(def′, :(=), :const,
-                 :global)      ?  vardoc(meta, def, namify(def′)) :
+    isexpr(def′, [:(=), :const,
+                 :global])     ?  vardoc(meta, def, namify(def′)) :
     isvar(def′)                ? objdoc(meta, def′) :
     isexpr(def′, :tuple)       ? multidoc(meta, def′.args) :
     __doc__!(meta, def′)       ? esc(def′) :

base/docs/bindings.jl

@@ -16,7 +16,7 @@ end
 splitexpr(s::Symbol) = :(current_module()), quot(s)
 splitexpr(other)     = error("Invalid @var syntax `$other`.")
 
-isvar(x) = isexpr(x, :macrocall, :.)
+isvar(x) = isexpr(x, [:macrocall, :.])
 isvar(::Symbol) = true
 
 macro var(x)

test/docs.jl

@@ -411,6 +411,9 @@ f12593_2() = 1
 # test that macro documentation works
 @test (Docs.@repl @assert) !== nothing
 
+# Issue #13467.
+@test (Docs.@repl @r_str) !== nothing
+
 # Simple tests for apropos:
 @test contains(sprint(apropos, "pearson"), "cov")
 @test contains(sprint(apropos, r"ind(exes|ices)"), "eachindex")