From 28af3b350bb2f6ab427e55e8cadbe539a5ef5a5e Mon Sep 17 00:00:00 2001
From: Kristoffer Carlsson <kristoffer.carlsson@chalmers.se>
Date: Mon, 4 Mar 2019 20:01:10 +0100
Subject: [PATCH] only break if we are throwing an uncaught exception (#89)

---
 src/interpret.jl    | 10 ++++++----
 test/breakpoints.jl | 29 +++++++++++++++++++----------
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/src/interpret.jl b/src/interpret.jl
index 8d317da2266c8d..f59f6e6fa9bc78 100644
--- a/src/interpret.jl
+++ b/src/interpret.jl
@@ -486,6 +486,11 @@ function step_expr!(stack, frame, istoplevel::Bool=false)
 end
 
 function handle_err(stack, frame, pc, err)
+    if !isempty(frame.exception_frames)
+        # Exception caught
+        frame.last_exception[] = err
+        return JuliaProgramCounter(frame.exception_frames[end])
+    end
     if break_on_error[]
         frame.pc[] = pc
         push!(stack, frame)
@@ -499,12 +504,9 @@ function handle_err(stack, frame, pc, err)
             hasmethod(err.f, arg_types) &&
             !hasmethod(err.f, arg_types, world = err.world))
             @warn "likely failure to return to toplevel, try JuliaInterpreter.split_expressions"
-            rethrow(err)
         end
     end
-    isempty(frame.exception_frames) && rethrow(err)
-    frame.last_exception[] = err
-    return JuliaProgramCounter(frame.exception_frames[end])
+    rethrow(err)
 end
 
 """
diff --git a/test/breakpoints.jl b/test/breakpoints.jl
index 3aef22c9ee75ed..80b288cdd040bf 100644
--- a/test/breakpoints.jl
+++ b/test/breakpoints.jl
@@ -84,14 +84,23 @@ end
     remove()
 
     # break on error
-    inner(x) = error("oops")
-    outer() = inner(1)
-    JuliaInterpreter.break_on_error[] = true
-    stack = JuliaStackFrame[]
-    frame = JuliaInterpreter.enter_call(outer)
-    bp = JuliaInterpreter.finish_and_return!(stack, frame)
-    @test bp.err == ErrorException("oops")
-    @test length(stack) >= 2
-    @test stack[1].code.scope.name == :outer
-    @test stack[2].code.scope.name == :inner
+    try
+        JuliaInterpreter.break_on_error[] = true
+
+        inner(x) = error("oops")
+        outer() = inner(1)
+        stack = JuliaStackFrame[]
+        frame = JuliaInterpreter.enter_call(outer)
+        bp = JuliaInterpreter.finish_and_return!(stack, frame)
+        @test bp.err == ErrorException("oops")
+        @test length(stack) >= 2
+        @test stack[1].code.scope.name == :outer
+        @test stack[2].code.scope.name == :inner
+
+        f_catch() = try error(); catch; return 2; end
+        @test @interpret f_catch() == 2
+
+    finally
+        JuliaInterpreter.break_on_error[] = false
+    end
 end