code review 13302051: runtime: show runtime.panic frame in traceback

src/pkg/runtime/symtab.c

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // Runtime symbol table parsing.
 // See http://golang.org/s/go12symtab for an overview.
 
 #include "runtime.h"
 #include "defs_GOOS_GOARCH.h"
 #include "os_GOOS.h"
@@ skipping 299 matching lines @@
         }
         return 0;
 }
 
 bool
 runtime·showframe(Func *f, G *gp)
 {
         static int32 traceback = -1;
         String name;
 
-        if(m->throwing && gp != nil && (gp == m->curg || gp == m->caughtsig))
+        if(m->throwing > 0 && gp != nil && (gp == m->curg || gp == m->caughtsig))
                 return 1;
         if(traceback < 0)
                 traceback = runtime·gotraceback(nil);
         name = runtime·gostringnocopy((uint8*)runtime·funcname(f));
+
+        // Special case: always show runtime.panic frame, so that we can
+        // see where a panic started in the middle of a stack trace.
+        // See golang.org/issue/5832.
+        if(name.len == 7+1+5 && hasprefix(name, "runtime.panic"))
+                return 1;
+
         return traceback > 1 || f != nil && contains(name, ".") && !hasprefix(name, "runtime.");
 }