bug 317476: The error thrown by JS_ReportError is not catchable. r=brendan

js/src/js.c

@@ -1612,6 +1612,13 @@ TestUtf8(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
     return !JS_IsExceptionPending (cx);
 }
 
+static JSBool
+ThrowError(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
+{
+    JS_ReportError(cx, "This is an error");
+    return JS_FALSE;
+}
+
 static JSFunctionSpec shell_functions[] = {
     {"version",         Version,        0},
     {"options",         Options,        0},
@@ -1627,6 +1634,7 @@ static JSFunctionSpec shell_functions[] = {
     {"pc2line",         PCToLine,       0},
     {"stringsAreUtf8",  StringsAreUtf8, 0},
     {"testUtf8",        TestUtf8,       1},
+    {"throwError",      ThrowError,     0},
 #ifdef DEBUG
     {"dis",             Disassemble,    1},
     {"dissrc",          DisassWithSrc,  1},
@@ -1668,6 +1676,7 @@ static char *shell_help_messages[] = {
     "pc2line(fun[, pc])     Map PC to line number",
     "stringsAreUTF8()       Check if strings are UTF-8 encoded",
     "testUTF8(mode)         Perform UTF-8 tests (modes are 1 to 4)",
+    "throwError()           Throw an error from JS_ReportError",
 #ifdef DEBUG
     "dis([fun])             Disassemble functions into bytecodes",
     "dissrc([fun])          Disassemble functions with source lines",

js/src/js.msg

@@ -285,3 +285,4 @@ MSG_DEF(JSMSG_BUFFER_TOO_SMALL,       202, 0, JSEXN_INTERNALERR, "buffer too sma
 MSG_DEF(JSMSG_BAD_SURROGATE_CHAR,     203, 1, JSEXN_TYPEERR, "bad surrogate character {0}")
 MSG_DEF(JSMSG_UTF8_CHAR_TOO_LARGE,    204, 1, JSEXN_TYPEERR, "UTF-8 character {0} too large")
 MSG_DEF(JSMSG_MALFORMED_UTF8_CHAR,    205, 1, JSEXN_TYPEERR, "malformed UTF-8 character sequence at offset {0}")
+MSG_DEF(JSMSG_USER_DEFINED_ERROR,     206, 0, JSEXN_ERR, "JS_ReportError was called")

js/src/jscntxt.c

@@ -758,7 +758,9 @@ js_ReportOutOfMemory(JSContext *cx, JSErrorCallback callback)
 JSBool
 js_ReportErrorVA(JSContext *cx, uintN flags, const char *format, va_list ap)
 {
-    char *last;
+    char *message;
+    jschar *ucmessage;
+    size_t messagelen;
     JSStackFrame *fp;
     JSErrorReport report;
     JSBool warning;
@@ -766,12 +768,15 @@ js_ReportErrorVA(JSContext *cx, uintN flags, const char *format, va_list ap)
     if ((flags & JSREPORT_STRICT) && !JS_HAS_STRICT_OPTION(cx))
         return JS_TRUE;
 
-    last = JS_vsmprintf(format, ap);
-    if (!last)
+    message = JS_vsmprintf(format, ap);
+    if (!message)
         return JS_FALSE;
+    messagelen = strlen(message);
 
     memset(&report, 0, sizeof (struct JSErrorReport));
     report.flags = flags;
+    report.errorNumber = JSMSG_USER_DEFINED_ERROR;
+    report.ucmessage = ucmessage = js_InflateString(cx, message, &messagelen);
 
     /* Find the top-most active script frame, for best line number blame. */
     for (fp = cx->fp; fp; fp = fp->down) {
@@ -788,8 +793,9 @@ js_ReportErrorVA(JSContext *cx, uintN flags, const char *format, va_list ap)
         warning = JS_FALSE;
     }
 
-    ReportError(cx, last, &report);
-    free(last);
+    ReportError(cx, message, &report);
+    free(message);
+    JS_free(cx, ucmessage);
     return warning;
 }