From caaaeca6afcb308ed848ec2e07f7cc19ff2cc26c Mon Sep 17 00:00:00 2001
From: "shaver%mozilla.org"
 <shaver%mozilla.org@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Sat, 24 Dec 2005 01:09:19 +0000
Subject: [PATCH] Bug 319490: return in finally should clear pending
 exceptions. r=mrbkap, sr=brendan.

git-svn-id: svn://10.0.0.236/trunk@186549 18797224-902f-48f8-a5cc-f745e15eee43
---
 mozilla/js/src/jsemit.c   | 18 ++++++++++++++++--
 mozilla/js/src/jsemit.h   |  7 +++++--
 mozilla/js/src/jsinterp.c |  2 ++
 mozilla/js/src/jsopcode.c |  6 ++++--
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/mozilla/js/src/jsemit.c b/mozilla/js/src/jsemit.c
index fcb53c7b607..af6602258d0 100644
--- a/mozilla/js/src/jsemit.c
+++ b/mozilla/js/src/jsemit.c
@@ -1193,12 +1193,12 @@ js_SetJumpOffset(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc,
 }
 
 JSBool
-js_InWithStatement(JSTreeContext *tc)
+js_InStatement(JSTreeContext *tc, JSStmtType type)
 {
     JSStmtInfo *stmt;
 
     for (stmt = tc->topStmt; stmt; stmt = stmt->down) {
-        if (stmt->type == STMT_WITH)
+        if (stmt->type == type)
             return JS_TRUE;
     }
     return JS_FALSE;
@@ -3872,6 +3872,20 @@ js_EmitTree(JSContext *cx, JSCodeGenerator *cg, JSParseNode *pn)
         break;
 
       case TOK_RETURN:
+        /*
+         * If we're in a finally clause, then returning must clear any pending
+         * exception state.  Failure to do so could cause a subsequent
+         * non-throwing API failure or native use of JS_IsPendingException to
+         * mislead.
+         */
+        if (js_InStatement(&cg->treeContext, STMT_SUBROUTINE) &&
+            (js_NewSrcNote(cx, cg, SRC_HIDDEN) < 0 ||
+             js_Emit1(cx, cg, JSOP_EXCEPTION) < 0 ||
+             js_NewSrcNote(cx, cg, SRC_HIDDEN) < 0 ||
+             js_Emit1(cx, cg, JSOP_POP) < 0)) {
+            return JS_FALSE;
+        }
+
         /* Push a return value */
         pn2 = pn->pn_kid;
         if (pn2) {
diff --git a/mozilla/js/src/jsemit.h b/mozilla/js/src/jsemit.h
index f83fe61c98a..2ea17e2b425 100644
--- a/mozilla/js/src/jsemit.h
+++ b/mozilla/js/src/jsemit.h
@@ -305,9 +305,12 @@ extern JSBool
 js_SetJumpOffset(JSContext *cx, JSCodeGenerator *cg, jsbytecode *pc,
                  ptrdiff_t off);
 
-/* Test whether we're in a with statement. */
+/* Test whether we're in a statement of given type. */
 extern JSBool
-js_InWithStatement(JSTreeContext *tc);
+js_InStatement(JSTreeContext *tc, JSStmtType type);
+
+/* Test whether we're in a with statement. */
+#define js_InWithStatement(tc)      js_InStatement(tc, STMT_WITH)
 
 /* Test whether we're in a catch block with exception named by atom. */
 extern JSBool
diff --git a/mozilla/js/src/jsinterp.c b/mozilla/js/src/jsinterp.c
index 5edd210e15e..e8578f97369 100644
--- a/mozilla/js/src/jsinterp.c
+++ b/mozilla/js/src/jsinterp.c
@@ -2099,6 +2099,7 @@ interrupt:
           END_CASE(JSOP_LEAVEWITH)
 
           BEGIN_CASE(JSOP_SETRVAL)
+            JS_ASSERT(!cx->throwing);
             fp->rval = POP_OPND();
           END_CASE(JSOP_SETRVAL)
 
@@ -2108,6 +2109,7 @@ interrupt:
             /* FALL THROUGH */
 
           BEGIN_CASE(JSOP_RETRVAL)    /* fp->rval already set */
+            JS_ASSERT(!cx->throwing);
             if (inlineCallCount)
           inline_return:
             {
diff --git a/mozilla/js/src/jsopcode.c b/mozilla/js/src/jsopcode.c
index c5d1e12f4d6..06dafcce8d0 100644
--- a/mozilla/js/src/jsopcode.c
+++ b/mozilla/js/src/jsopcode.c
@@ -1232,8 +1232,10 @@ Decompile(SprintStack *ss, jsbytecode *pc, intN nb)
 
               case JSOP_EXCEPTION:
                 /*
-                 * The only other JSOP_EXCEPTION case occurs as part of a code
-                 * sequence that follows a SRC_CATCH-annotated JSOP_NOP.
+                 * The only other JSOP_EXCEPTION cases occur as part of a code
+                 * sequence that follows a SRC_CATCH-annotated JSOP_NOP or
+                 * precedes a SRC_HIDDEN-annotated JSOP_POP emitted when
+                 * returning from within a finally clause.
                  */
                 sn = js_GetSrcNote(jp->script, pc);
                 LOCAL_ASSERT(sn && SN_TYPE(sn) == SRC_HIDDEN);