diff --git a/include/QF/progs.h b/include/QF/progs.h
index fd36c0c62..7ccb962d2 100644
--- a/include/QF/progs.h
+++ b/include/QF/progs.h
@@ -1742,6 +1742,7 @@ pr_auxfunction_t *PR_Get_Lineno_Func (progs_t *pr, pr_lineno_t *lineno) __attrib
 pr_uint_t PR_Get_Lineno_Addr (progs_t *pr, pr_lineno_t *lineno) __attribute__((pure));
 pr_uint_t PR_Get_Lineno_Line (progs_t *pr, pr_lineno_t *lineno) __attribute__((pure));
 pr_lineno_t *PR_Find_Lineno (progs_t *pr, pr_uint_t addr) __attribute__((pure));
+pr_uint_t PR_FindSourceLineAddr (progs_t *pr, const char *file, pr_uint_t line) __attribute__((pure));
 const char *PR_Get_Source_File (progs_t *pr, pr_lineno_t *lineno) __attribute__((pure));
 const char *PR_Get_Source_Line (progs_t *pr, pr_uint_t addr);
 pr_def_t *PR_Get_Param_Def (progs_t *pr, dfunction_t *func, unsigned parm) __attribute__((pure));
diff --git a/libs/gamecode/pr_debug.c b/libs/gamecode/pr_debug.c
index 3ef208442..906ec185f 100644
--- a/libs/gamecode/pr_debug.c
+++ b/libs/gamecode/pr_debug.c
@@ -31,6 +31,8 @@
 # include "config.h"
 #endif
 
+#define _GNU_SOURCE	// for qsort_r
+
 #ifdef HAVE_STRING_H
 # include <string.h>
 #endif
@@ -41,6 +43,7 @@
 #include <sys/types.h>
 #include <stdlib.h>
 
+#include "QF/fbsearch.h"
 #include "QF/cvar.h"
 #include "QF/dstring.h"
 #include "QF/hash.h"
@@ -75,6 +78,11 @@ typedef struct compunit_s {
 	pr_compunit_t *unit;
 } compunit_t;
 
+typedef struct {
+	const char *file;
+	pr_uint_t   line;
+} func_key_t;
+
 typedef struct prdeb_resources_s {
 	progs_t    *pr;
 	dstring_t  *string;
@@ -85,6 +93,7 @@ typedef struct prdeb_resources_s {
 	pr_debug_header_t *debug;
 	pr_auxfunction_t *auxfunctions;
 	pr_auxfunction_t **auxfunction_map;
+	func_t     *sorted_functions;
 	pr_lineno_t *linenos;
 	pr_def_t   *local_defs;
 	pr_def_t   *type_encodings_def;
@@ -379,6 +388,9 @@ pr_debug_clear (progs_t *pr, void *data)
 	if (res->auxfunction_map)
 		pr->free_progs_mem (pr, res->auxfunction_map);
 	res->auxfunction_map = 0;
+	if (res->sorted_functions)
+		pr->free_progs_mem (pr, res->sorted_functions);
+	res->sorted_functions = 0;
 	res->linenos = 0;
 	res->local_defs = 0;
 
@@ -478,6 +490,43 @@ process_compunit (prdeb_resources_t *res, pr_def_t *def)
 	}
 }
 
+static int
+func_compare_sort (const void *_fa, const void *_fb, void *_res)
+{
+	prdeb_resources_t *res = _res;
+	progs_t    *pr = res->pr;
+	func_t      fa = *(const func_t *)_fa;
+	func_t      fb = *(const func_t *)_fb;
+	const char *fa_file = PR_GetString (pr, pr->pr_functions[fa].s_file);
+	const char *fb_file = PR_GetString (pr, pr->pr_functions[fb].s_file);
+	int         cmp = strcmp (fa_file, fb_file);
+	if (cmp) {
+		return cmp;
+	}
+	pr_auxfunction_t *fa_aux = res->auxfunction_map[fa];
+	pr_auxfunction_t *fb_aux = res->auxfunction_map[fb];
+	pr_uint_t   fa_line = fa_aux ? fa_aux->source_line : 0;
+	pr_uint_t   fb_line = fb_aux ? fb_aux->source_line : 0;
+	return fa_line - fb_line;
+}
+
+static int
+func_compare_search (const void *_key, const void *_f, void *_res)
+{
+	prdeb_resources_t *res = _res;
+	progs_t    *pr = res->pr;
+	const func_key_t *key = _key;
+	func_t      f = *(const func_t *)_f;
+	const char *f_file = PR_GetString (pr, pr->pr_functions[f].s_file);
+	int         cmp = strcmp (key->file, f_file);
+	if (cmp) {
+		return cmp;
+	}
+	pr_auxfunction_t *f_aux = res->auxfunction_map[f];
+	pr_uint_t   f_line = f_aux ? f_aux->source_line : 0;
+	return key->line - f_line;
+}
+
 VISIBLE int
 PR_LoadDebug (progs_t *pr)
 {
@@ -562,8 +611,12 @@ PR_LoadDebug (progs_t *pr)
 
 	i = pr->progs->numfunctions * sizeof (pr_auxfunction_t *);
 	res->auxfunction_map = pr->allocate_progs_mem (pr, i);
-	for (i = 0; i < pr->progs->numfunctions; i++)
+	i = pr->progs->numfunctions * sizeof (func_t);
+	res->sorted_functions = pr->allocate_progs_mem (pr, i);
+	for (i = 0; i < pr->progs->numfunctions; i++) {
 		res->auxfunction_map[i] = 0;
+		res->sorted_functions[i] = i;
+	}
 
 	res->type_encodings_def = PR_FindGlobal (pr, ".type_encodings");
 	if (res->type_encodings_def) {
@@ -593,6 +646,8 @@ PR_LoadDebug (progs_t *pr)
 		res->linenos[i].fa.func = LittleLong (res->linenos[i].fa.func);
 		res->linenos[i].line = LittleLong (res->linenos[i].line);
 	}
+	qsort_r (res->sorted_functions, pr->progs->numfunctions, sizeof (func_t),
+			 func_compare_sort, res);
 	for (i = 0; i < res->debug->num_locals; i++) {
 		byteswap_def (&res->local_defs[i]);
 		if (type_encodings) {
@@ -752,6 +807,43 @@ PR_Find_Lineno (progs_t *pr, pr_uint_t addr)
 	return lineno;
 }
 
+pr_uint_t
+PR_FindSourceLineAddr (progs_t *pr, const char *file, pr_uint_t line)
+{
+	prdeb_resources_t *res = pr->pr_debug_resources;
+	func_key_t  key = { file, line };
+	func_t     *f = fbsearch_r (&key, res->sorted_functions,
+								pr->progs->numfunctions, sizeof (func_t),
+								func_compare_search, res);
+	if (!f) {
+		return 0;
+	}
+	dfunction_t *func = &pr->pr_functions[*f];
+	if (func->first_statement <= 0
+		|| strcmp (file, PR_GetString (pr, func->s_file)) != 0) {
+		return 0;
+	}
+	pr_auxfunction_t *aux = res->auxfunction_map[*f];
+	if (!aux) {
+		return 0;
+	}
+	pr_uint_t   addr = func->first_statement;
+	line -= aux->source_line;
+
+	//FIXME put lineno count in sym file
+	for (pr_uint_t i = aux->line_info + 1; i < res->debug->num_linenos; i++) {
+		if (!res->linenos[i].line) {
+			break;
+		}
+		if (res->linenos[i].line <= line) {
+			addr = res->linenos[i].fa.addr;
+		} else {
+			break;
+		}
+	}
+	return addr;
+}
+
 const char *
 PR_Get_Source_File (progs_t *pr, pr_lineno_t *lineno)
 {
diff --git a/ruamoko/qwaq/builtins/debug.c b/ruamoko/qwaq/builtins/debug.c
index fe6796b46..5d6c598ed 100644
--- a/ruamoko/qwaq/builtins/debug.c
+++ b/ruamoko/qwaq/builtins/debug.c
@@ -225,8 +225,9 @@ qdb_set_breakpoint (progs_t *pr)
 		R_INT (pr) = -1;
 		return;
 	}
+	int         set = (tpr->pr_statements[staddr].op & OP_BREAK) != 0;
 	tpr->pr_statements[staddr].op |= OP_BREAK;
-	R_INT (pr) = 0;
+	R_INT (pr) = set;
 }
 
 static void
@@ -619,6 +620,19 @@ qdb_get_local_defs (progs_t *pr)
 	}
 }
 
+static void
+qdb_get_source_line_addr (progs_t *pr)
+{
+	__auto_type debug = PR_Resources_Find (pr, "qwaq-debug");
+	pointer_t   handle = P_INT (pr, 0);
+	qwaq_target_t *target = get_target (debug, __FUNCTION__, handle);
+	progs_t    *tpr = target->pr;
+	const char *file = P_GSTRING (pr, 1);
+	pr_uint_t   line = P_UINT (pr, 2);
+
+	R_UINT (pr) = PR_FindSourceLineAddr (tpr, file, line);
+}
+
 static builtin_t builtins[] = {
 	{"qdb_set_trace",			qdb_set_trace,			-1},
 	{"qdb_set_breakpoint",		qdb_set_breakpoint,		-1},
@@ -641,6 +655,7 @@ static builtin_t builtins[] = {
 	{"qdb_find_auxfunction",	qdb_find_auxfunction,	-1},
 	{"qdb_get_auxfunction",		qdb_get_auxfunction,	-1},
 	{"qdb_get_local_defs",		qdb_get_local_defs,		-1},
+	{"qdb_get_source_line_addr", qdb_get_source_line_addr, -1},
 	{}
 };
 
diff --git a/ruamoko/qwaq/debugger/debug.h b/ruamoko/qwaq/debugger/debug.h
index f6f58f5ed..2e68de316 100644
--- a/ruamoko/qwaq/debugger/debug.h
+++ b/ruamoko/qwaq/debugger/debug.h
@@ -95,7 +95,8 @@ qdb_function_t *qdb_get_function (qdb_target_t target, unsigned fnum);
 qdb_auxfunction_t *qdb_find_auxfunction (qdb_target_t target, string name);
 qdb_auxfunction_t *qdb_get_auxfunction (qdb_target_t target, unsigned fnum);
 qdb_def_t *qdb_get_local_defs (qdb_target_t target, unsigned fnum);
-
+unsigned qdb_get_source_line_addr(qdb_target_t target, string file,
+								  unsigned line);
 void traceon();
 void traceoff();
 
diff --git a/ruamoko/qwaq/debugger/debug.r b/ruamoko/qwaq/debugger/debug.r
index feb8adbdd..70126f7a2 100644
--- a/ruamoko/qwaq/debugger/debug.r
+++ b/ruamoko/qwaq/debugger/debug.r
@@ -27,3 +27,5 @@ qdb_auxfunction_t *qdb_find_auxfunction (qdb_target_t target,
 qdb_auxfunction_t *qdb_get_auxfunction (qdb_target_t target,
 										unsigned fnum) = #0;
 qdb_def_t *qdb_get_local_defs (qdb_target_t target, unsigned fnum) = #0;
+unsigned qdb_get_source_line_addr(qdb_target_t target, string file,
+								  unsigned line) = #0;
diff --git a/ruamoko/qwaq/debugger/debugger.h b/ruamoko/qwaq/debugger/debugger.h
index 8694d06c0..46c9cbeda 100644
--- a/ruamoko/qwaq/debugger/debugger.h
+++ b/ruamoko/qwaq/debugger/debugger.h
@@ -28,6 +28,7 @@
 		int         onExit;
 	}           sub_cond;
 	SEL         traceHandler;
+	SEL         breakHandler;
 	int         running;
 
 	Window     *source_window;
diff --git a/ruamoko/qwaq/debugger/debugger.r b/ruamoko/qwaq/debugger/debugger.r
index 3acf1707e..aabb06889 100644
--- a/ruamoko/qwaq/debugger/debugger.r
+++ b/ruamoko/qwaq/debugger/debugger.r
@@ -53,17 +53,17 @@
 -(Editor *) find_file:(string) filename
 {
 	Editor     *file;
-	filename = qdb_get_file_path (target, filename);
+	string      filepath = qdb_get_file_path (target, filename);
 	for (int i = [files count]; i-- > 0; ) {
 		file = [files objectAtIndex: i];
-		if ([file filename] == filename) {
+		if ([file filepath] == filepath) {
 			return file;
 		}
 	}
 	Rect rect = {{1, 1}, [source_window size]};
 	rect.extent.width -= 2;
 	rect.extent.height -= 2;
-	file = [Editor withRect:rect file:filename];
+	file = [Editor withRect:rect file:filename path:filepath];
 	[files addObject: file];
 	return file;
 }
@@ -154,6 +154,27 @@ proxy_event_stopped (Debugger *self, id proxy, qwaq_event_t *event)
 				self.running = 1;
 				qdb_continue (self.target);
 				return 1;
+			case QFK_F4:
+				string      file = [self.current_file filename];
+				unsigned    line = [self.current_file cursor].y + 1;
+				unsigned    addr = qdb_get_source_line_addr (self.target,
+															 file, line);
+				int         set = -1;
+				if (addr) {
+					set = qdb_set_breakpoint (self.target, addr);
+				}
+				if (set >= 0) {
+					qdb_set_trace (self.target, 0);
+					if (set) {
+						self.breakHandler = @selector(breakKeep);
+					} else {
+						self.breakHandler = @selector(breakClear);
+					}
+					self.running = 1;
+					qdb_continue (self.target);
+				} else {
+				}
+				return 1;
 		}
 	}
 	return 0;
@@ -236,6 +257,18 @@ is_new_line (qdb_state_t last_state, qdb_state_t state)
 	return self;
 }
 
+-breakKeep
+{
+	return self;
+}
+
+-breakClear
+{
+	qdb_state_t state = qdb_get_state (target);
+	qdb_clear_breakpoint (target, state.staddr);
+	return self;
+}
+
 -handleDebugEvent
 {
 	if (qdb_get_event (target, &event)) {
@@ -247,6 +280,7 @@ is_new_line (qdb_state_t last_state, qdb_state_t state)
 				break;
 			case prd_breakpoint:
 			case prd_watchpoint:
+				[self performSelector:breakHandler];
 				[self stop:event.what];
 				break;
 			case prd_subenter:
diff --git a/ruamoko/qwaq/gcd.r b/ruamoko/qwaq/gcd.r
index bfa3a5e84..a01cce830 100644
--- a/ruamoko/qwaq/gcd.r
+++ b/ruamoko/qwaq/gcd.r
@@ -13,7 +13,6 @@ gcd (int a, int b)
 int
 main (int argc, string *argv)
 {
-	traceon ();
 	x = 130;
 	y = 120;
 	printf ("%d\n", gcd (x, y));