bug 129519, "JS_GetPropertyDesc gives up too easily", r=jband, sr=shaver, a=bren

dan
Reflect new JSPD_* defines, make jsd_GetValueProperty degrade gracefully instead of fail outright when we run into a problem fetching the property value.

js/jsd/idl/jsdIDebuggerService.idl

@@ -1151,7 +1151,11 @@ interface jsdIProperty : jsdIEphemeral
     const unsigned long FLAG_ARGUMENT  = 0x10;
     /** local variable in function */
     const unsigned long FLAG_VARIABLE  = 0x20;
-    /** found via explicit lookup */
+    /** exception occurred looking up property, value is exception */
+    const unsigned long FLAG_EXCEPTION = 0x40;
+    /** native getter returned JS_FALSE without throwing an exception */
+    const unsigned long FLAG_ERROR     = 0x80;
+    /** found via explicit lookup (property defined elsewhere.) */
     const unsigned long FLAG_HINTED    = 0x800;
 
     /** FLAG_* values OR'd together, representing the flags for this property. */

js/jsd/jsd_val.c

@@ -462,21 +462,34 @@ jsd_GetValueProperty(JSDContext* jsdc, JSDValue* jsdval, JSString* name)
     nameChars = JS_GetStringChars(name);
     nameLen   = JS_GetStringLength(name);
 
-    /* It's OK if this fails - we just don't get attribs */
     JS_GetUCPropertyAttributes(cx, obj, nameChars, nameLen, &attrs, &found);
+    if (!found)
+        return NULL;
+
+    JS_ClearPendingException(cx);
 
     if(!JS_GetUCProperty(cx, obj, nameChars, nameLen, &val))
-        return NULL;
-
-    /* XXX screwy! no good way to detect that property does not exist at all */
-    if(!found && JSVAL_IS_VOID(val))
-        return NULL;
+    {
+        if (JS_IsExceptionPending(cx))
+        {
+            if (!JS_GetPendingException(cx, &pd.value))
+                return NULL;
+            pd.flags = JSPD_EXCEPTION;
+        }
+        else
+        {
+            pd.flags = JSPD_ERROR;
+            pd.value = JSVAL_VOID;
+        }
+    }
+    else
+    {
+        pd.value = val;
+    }
 
     pd.id = STRING_TO_JSVAL(name);
-    pd.value = val;
     pd.alias = pd.slot = pd.spare = 0;
-    pd.flags = 0
-        | (attrs & JSPROP_ENUMERATE) ? JSPD_ENUMERATE : 0
+    pd.flags |= (attrs & JSPROP_ENUMERATE) ? JSPD_ENUMERATE : 0
         | (attrs & JSPROP_READONLY)  ? JSPD_READONLY  : 0
         | (attrs & JSPROP_PERMANENT) ? JSPD_PERMANENT : 0;
 

js/jsd/jsdebug.h

@@ -56,6 +56,7 @@ extern "C"
 
 JS_BEGIN_EXTERN_C
 #include "jsapi.h"
+#include "jsdbgapi.h"
 #ifdef LIVEWIRE
 #include "lwdbgapi.h"
 #endif
@@ -1293,14 +1294,18 @@ JSD_GetValueClassName(JSDContext* jsdc, JSDValue* jsdval);
  *
  * XXX these must stay the same as the JSPD_ flags in jsdbgapi.h
  */
-#define JSDPD_ENUMERATE  0x01    /* visible to for/in loop */
-#define JSDPD_READONLY   0x02    /* assignment is error */
-#define JSDPD_PERMANENT  0x04    /* property cannot be deleted */
-#define JSDPD_ALIAS      0x08    /* property has an alias id */
-#define JSDPD_ARGUMENT   0x10    /* argument to function */
-#define JSDPD_VARIABLE   0x20    /* local variable in function */
+#define JSDPD_ENUMERATE  JSPD_ENUMERATE    /* visible to for/in loop */
+#define JSDPD_READONLY   JSPD_READONLY     /* assignment is error */
+#define JSDPD_PERMANENT  JSPD_PERMANENT    /* property cannot be deleted */
+#define JSDPD_ALIAS      JSPD_ALIAS        /* property has an alias id */
+#define JSDPD_ARGUMENT   JSPD_ARGUMENT     /* argument to function */
+#define JSDPD_VARIABLE   JSPD_VARIABLE     /* local variable in function */
+#define JSDPD_EXCEPTION  JSPD_EXCEPTION    /* exception occurred looking up */
+                                           /* proprety, value is exception  */
+#define JSDPD_ERROR      JSPD_ERROR        /* native getter returned JS_FALSE */
+                                           /* without throwing an exception */
 /* this is not one of the JSPD_ flags in jsdbgapi.h  - careful not to overlap*/
-#define JSDPD_HINTED     0x800   /* found via explicit lookup */
+#define JSDPD_HINTED     0x800             /* found via explicit lookup */
 
 /*
 * Release this JSDProperty