From b73d097d36d3fb3046fcb0c190c02684cd0c1867 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arne=20D=C3=B6ring?= <arne.doering@gmx.net>
Date: Sun, 4 Aug 2019 19:31:55 +0200
Subject: [PATCH] fixes #9829 (#11849)

---
 compiler/vmgen.nim              |  2 +-
 tests/vm/tmaxloopiterations.nim | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 tests/vm/tmaxloopiterations.nim

diff --git a/compiler/vmgen.nim b/compiler/vmgen.nim
index a27cd62c6..d1ed78bf2 100644
--- a/compiler/vmgen.nim
+++ b/compiler/vmgen.nim
@@ -2160,7 +2160,7 @@ proc optimizeJumps(c: PCtx; start: int) =
       var d = i + c.code[i].jmpDiff
       for iters in countdown(maxIterations, 0):
         case c.code[d].opcode
-        of opcJmp, opcJmpBack:
+        of opcJmp:
           d = d + c.code[d].jmpDiff
         of opcTJmp, opcFJmp:
           if c.code[d].regA != reg: break
diff --git a/tests/vm/tmaxloopiterations.nim b/tests/vm/tmaxloopiterations.nim
new file mode 100644
index 000000000..6334d1e6d
--- /dev/null
+++ b/tests/vm/tmaxloopiterations.nim
@@ -0,0 +1,15 @@
+discard """
+errormsg: "interpretation requires too many iterations; if you are sure this is not a bug in your code edit compiler/vmdef.MaxLoopIterations and rebuild the compiler"
+"""
+
+# issue #9829
+
+macro foo(): untyped  =
+  let lines = ["123", "5423"]
+  var idx = 0
+  while idx < lines.len():
+    if lines[idx].len() < 1:
+      inc(idx)
+      continue
+
+foo()