From 3abe1ffb27768d6eff8326c93071b29e91bbeba5 Mon Sep 17 00:00:00 2001
From: Jacob Quinn <quinn.jacobd@gmail.com>
Date: Fri, 30 Jul 2021 00:29:54 -0600
Subject: [PATCH] Fix case when float parsing, we failed to check eof before
 peeking

Discovered while porting JSON.jl to Parsers 2.0. Unfortunately, the byte
peeking was under an `@inbounds`, so this usually wouldn't error unless
julia was run with `--check-bounds=yes` (which is the default when
running tests thankfully). Good candidate to backport for another 1.X
release.
---
 src/floats.jl  | 5 +++++
 test/floats.jl | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/src/floats.jl b/src/floats.jl
index d6ec4b5..b5ce7be 100644
--- a/src/floats.jl
+++ b/src/floats.jl
@@ -291,6 +291,11 @@ end
         if negexp || b == UInt8('+')
             pos += 1
             incr!(source)
+            if eof(source, pos, len)
+                # it's an error to have a "dangling" '-' or '+', so input was something like "1.1e-"
+                code |= INVALID | EOF
+                @goto done
+            end
         end
         b = peekbyte(source, pos) - UInt8('0')
         if b > 0x09
diff --git a/test/floats.jl b/test/floats.jl
index 820a35e..c2c7217 100644
--- a/test/floats.jl
+++ b/test/floats.jl
@@ -363,4 +363,7 @@ for _ = 1:1000
     @test Base.parse(Float16, str) === Parsers.parse(Float16, str)
 end
 
+# discovered from JSON tests
+@test Parsers.tryparse(Float64, "0e+") === nothing
+
 end # @testset