Fix SF bug #765624.

diff --git a/Python/ceval.c b/Python/ceval.c
index d3a0053f61563b170b81ab981d66766641b6943e..b48e042e208dd089bc50c5a8dabf6aa6e465fda8 100644 (file)
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -48,7 +48,7 @@ static void call_trace_protected(Py_tracefunc, PyObject *,
                                 PyFrameObject *, int);
 static void call_exc_trace(Py_tracefunc, PyObject *, PyFrameObject *);
 static int maybe_call_line_trace(Py_tracefunc, PyObject *, 
-                                 PyFrameObject *, int *, int *);
+                                 PyFrameObject *, int *, int *, int *);
 
 static PyObject *apply_slice(PyObject *, PyObject *, PyObject *);
 static int assign_slice(PyObject *, PyObject *,
@@ -602,7 +602,7 @@ eval_frame(PyFrameObject *f)
           is true when the line being executed has changed.  The 
            initial values are such as to make this false the first
            time it is tested. */
-       int instr_ub = -1, instr_lb = 0;
+       int instr_ub = -1, instr_lb = 0, instr_prev = -1;
 
        unsigned char *first_instr;
        PyObject *names;
@@ -846,7 +846,8 @@ eval_frame(PyFrameObject *f)
                        
                        err = maybe_call_line_trace(tstate->c_tracefunc,
                                                    tstate->c_traceobj,
-                                                   f, &instr_lb, &instr_ub);
+                                                   f, &instr_lb, &instr_ub,
+                                                   &instr_prev);
                        /* Reload possibly changed frame fields */
                        JUMPTO(f->f_lasti);
                        if (f->f_stacktop != NULL) {
@@ -3085,7 +3086,8 @@ _PyEval_CallTracing(PyObject *func, PyObject *args)
 
 static int
 maybe_call_line_trace(Py_tracefunc func, PyObject *obj, 
-                     PyFrameObject *frame, int *instr_lb, int *instr_ub)
+                     PyFrameObject *frame, int *instr_lb, int *instr_ub,
+                     int *instr_prev)
 {
        /* The theory of SET_LINENO-less tracing.
           
@@ -3209,7 +3211,12 @@ maybe_call_line_trace(Py_tracefunc func, PyObject *obj,
                        *instr_ub = INT_MAX;
                }
        }
-
+       else if (frame->f_lasti <= *instr_prev) {
+               /* jumping back in the same line forces a trace event */
+               result = call_trace(func, obj, frame, 
+                                   PyTrace_LINE, Py_None);
+       }
+       *instr_prev = frame->f_lasti;
        return result;
 }