From ec626f2584d63ba46eb4fee082233d7b92095885 Mon Sep 17 00:00:00 2001
From: Tim Holy <tim.holy@gmail.com>
Date: Fri, 15 Mar 2019 04:27:50 -0500
Subject: [PATCH] Run callbacks inside try/catch

---
 src/CodeTracking.jl | 27 ++++++++++++++++++---------
 test/runtests.jl    |  4 ++++
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/src/CodeTracking.jl b/src/CodeTracking.jl
index a21fc46..8b76555 100644
--- a/src/CodeTracking.jl
+++ b/src/CodeTracking.jl
@@ -33,9 +33,12 @@ function whereis(method::Method)
     if lin === nothing
         f = method_lookup_callback[]
         if f !== nothing
-            Base.invokelatest(f, method)
+            try
+                Base.invokelatest(f, method)
+                lin = get(method_info, method.sig, nothing)
+            catch
+            end
         end
-        lin = get(method_info, method.sig, nothing)
     end
     if lin === nothing
         file, line = String(method.file), method.line
@@ -115,12 +118,15 @@ end
 function signatures_at(id::PkgId, relpath::AbstractString, line::Integer)
     expressions = expressions_callback[]
     expressions === nothing && error("cannot look up methods by line number, try `using Revise` before loading other packages")
-    for (mod, exsigs) in Base.invokelatest(expressions, id, relpath)
-        for (ex, sigs) in exsigs
-            lr = linerange(ex)
-            lr === nothing && continue
-            line ∈ lr && return sigs
+    try
+        for (mod, exsigs) in Base.invokelatest(expressions, id, relpath)
+            for (ex, sigs) in exsigs
+                lr = linerange(ex)
+                lr === nothing && continue
+                line ∈ lr && return sigs
+            end
         end
+    catch
     end
     return nothing
 end
@@ -167,9 +173,12 @@ function definition(method::Method, ::Type{Expr})
     if def === nothing
         f = method_lookup_callback[]
         if f !== nothing
-            Base.invokelatest(f, method)
+            try
+                Base.invokelatest(f, method)
+                def = get(method_info, method.sig, nothing)
+            catch
+            end
         end
-        def = get(method_info, method.sig, nothing)
     end
     return def === nothing ? nothing : copy(def[2])
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index 0badd71..6c575c3 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -50,4 +50,8 @@ include("script.jl")
     eval(ex)
     m = first(methods(replfunc))
     @test whereis(m) == ("REPL[1]", 1)
+
+    # Test with broken lookup
+    CodeTracking.method_lookup_callback[] = m -> error("oops")
+    @test whereis(m) == ("REPL[1]", 1)
 end