Change the nsICSSParser::Parse() API so that we don't hand out a stylesheet;

require a stylesheet to be set before calling Parse().  Bug 404315,
r+sr=dbaron, a=beltzner

layout/style/nsCSSLoader.cpp

@@ -438,6 +438,9 @@ CSSLoaderImpl::RecycleParser(nsICSSParser* aParser)
   if (!gParsers->AppendObject(aParser)) {
     return NS_ERROR_FAILURE;
   }
+
+  // Make sure the parser doesn't keep the last sheet it parsed alive
+  aParser->SetStyleSheet(nsnull);
   
   return NS_OK;
 }
@@ -1497,9 +1500,6 @@ CSSLoaderImpl::ParseSheet(nsIUnicharInputStream* aStream,
     return rv;
   }
 
-  // The parser insists on passing out a strong ref to the sheet it
-  // parsed.  We don't care.
-  nsCOMPtr<nsICSSStyleSheet> dummySheet;
   // Push our load data on the stack so any kids can pick it up
   mParsingDatas.AppendElement(aLoadData);
   nsCOMPtr<nsIURI> sheetURI, baseURI;
@@ -1507,8 +1507,7 @@ CSSLoaderImpl::ParseSheet(nsIUnicharInputStream* aStream,
   aLoadData->mSheet->GetBaseURI(getter_AddRefs(baseURI));
   rv = parser->Parse(aStream, sheetURI, baseURI,
                      aLoadData->mSheet->Principal(), aLoadData->mLineNumber,
-                     aLoadData->mAllowUnsafeRules,
-                     *getter_AddRefs(dummySheet));
+                     aLoadData->mAllowUnsafeRules);
   mParsingDatas.RemoveElementAt(mParsingDatas.Count() - 1);
   RecycleParser(parser);
 

layout/style/nsCSSParser.cpp

@@ -110,8 +110,7 @@ public:
                    nsIURI*                aBaseURI,
                    nsIPrincipal*          aSheetPrincipal,
                    PRUint32               aLineNumber,
-                   PRBool                 aAllowUnsafeRules,
-                   nsICSSStyleSheet*&     aResult);
+                   PRBool                 aAllowUnsafeRules);
 
   NS_IMETHOD ParseStyleAttribute(const nsAString&  aAttributeValue,
                                  nsIURI*           aDocURL,
@@ -584,16 +583,15 @@ CSSParserImpl::~CSSParserImpl()
 NS_IMETHODIMP
 CSSParserImpl::SetStyleSheet(nsICSSStyleSheet* aSheet)
 {
-  NS_PRECONDITION(nsnull != aSheet, "null ptr");
-  if (nsnull == aSheet) {
-    return NS_ERROR_NULL_POINTER;
-  }
-
   if (aSheet != mSheet) {
-    // Switch to using the new sheet
+    // Switch to using the new sheet, if any
     mGroupStack.Clear();
     mSheet = aSheet;
-    mNameSpaceMap = mSheet->GetNameSpaceMap();
+    if (mSheet) {
+      mNameSpaceMap = mSheet->GetNameSpaceMap();
+    } else {
+      mNameSpaceMap = nsnull;
+    }
   }
 
   return NS_OK;
@@ -684,6 +682,7 @@ CSSParserImpl::ReleaseScanner(void)
 #endif
   mBaseURL = nsnull;
   mSheetURL = nsnull;
+  mSheetPrincipal = nsnull;
   return NS_OK;
 }
 
@@ -694,34 +693,26 @@ CSSParserImpl::Parse(nsIUnicharInputStream* aInput,
                      nsIURI*                aBaseURI,
                      nsIPrincipal*          aSheetPrincipal,
                      PRUint32               aLineNumber,
-                     PRBool                 aAllowUnsafeRules,
-                     nsICSSStyleSheet*&     aResult)
+                     PRBool                 aAllowUnsafeRules)
 {
   NS_PRECONDITION(aSheetPrincipal, "Must have principal here!");
   
   NS_ASSERTION(nsnull != aBaseURI, "need base URL");
   NS_ASSERTION(nsnull != aSheetURI, "need sheet URL");
 
-  if (! mSheet) {
-    NS_NewCSSStyleSheet(getter_AddRefs(mSheet));
-    NS_ENSURE_TRUE(mSheet, NS_ERROR_OUT_OF_MEMORY);
+  NS_PRECONDITION(mSheet, "Must have sheet to parse into");
+  NS_ENSURE_STATE(mSheet);
 
-    mSheet->SetURIs(aSheetURI, aSheetURI, aBaseURI);
-    mSheet->SetPrincipal(aSheetPrincipal);
-    mNameSpaceMap = nsnull;
-  }
 #ifdef DEBUG
-  else {
-    nsCOMPtr<nsIURI> uri;
-    mSheet->GetSheetURI(getter_AddRefs(uri));
-    PRBool equal;
-    NS_ASSERTION(NS_SUCCEEDED(aSheetURI->Equals(uri, &equal)) && equal,
-                 "Sheet URI does not match passed URI");
-    NS_ASSERTION(NS_SUCCEEDED(mSheet->Principal()->Equals(aSheetPrincipal,
-                                                          &equal)) &&
-                 equal,
-                 "Sheet principal does not match passed principal");
-  }
+  nsCOMPtr<nsIURI> uri;
+  mSheet->GetSheetURI(getter_AddRefs(uri));
+  PRBool equal;
+  NS_ASSERTION(NS_SUCCEEDED(aSheetURI->Equals(uri, &equal)) && equal,
+               "Sheet URI does not match passed URI");
+  NS_ASSERTION(NS_SUCCEEDED(mSheet->Principal()->Equals(aSheetPrincipal,
+                                                        &equal)) &&
+               equal,
+               "Sheet principal does not match passed principal");
 #endif
   
   nsresult errorCode = NS_OK;
@@ -784,9 +775,6 @@ CSSParserImpl::Parse(nsIUnicharInputStream* aInput,
 
   mUnsafeRulesEnabled = PR_FALSE;
 
-  aResult = mSheet;
-  NS_ADDREF(aResult);
-
   return NS_OK;
 }
 

layout/style/nsCSSScanner.cpp

@@ -190,7 +190,7 @@ nsCSSScanner::nsCSSScanner()
     BuildLexTable();
   }
   mPushback = mLocalPushback;
-  mPushbackSize = 4;
+  mPushbackSize = NS_ARRAY_LENGTH(mLocalPushback);
   // No need to init the other members, since they represent state
   // which can get cleared.  We'll init them every time Init() is
   // called.
@@ -456,6 +456,16 @@ void nsCSSScanner::Close()
 {
   mInputStream = nsnull;
   mReadPointer = nsnull;
+
+  // Clean things up so we don't hold on to memory if our parser gets recycled.
+  mFileName.Truncate();
+  mURI = nsnull;
+  mError.Truncate();
+  if (mPushback != mLocalPushback) {
+    delete [] mPushback;
+    mPushback = mLocalPushback;
+    mPushbackSize = NS_ARRAY_LENGTH(mLocalPushback);
+  }
 }
 
 #ifdef CSS_REPORT_PARSE_ERRORS

layout/style/nsICSSParser.h

@@ -57,8 +57,8 @@ class nsMediaList;
 class nsIPrincipal;
 
 #define NS_ICSS_PARSER_IID    \
-{ 0x2cb34728, 0x0f17, 0x4753, \
-  {0x8e, 0xad, 0xec, 0x73, 0xe5, 0x69, 0xcd, 0xcd} }
+{ 0xad4a3778, 0xdae0, 0x4640, \
+ { 0xb2, 0x5a, 0x24, 0xff, 0x09, 0xc3, 0x70, 0xef } }
 
 // Rule processing function
 typedef void (*PR_CALLBACK RuleAppendFunc) (nsICSSRule* aRule, void* aData);
@@ -69,7 +69,8 @@ public:
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICSS_PARSER_IID)
 
   // Set a style sheet for the parser to fill in. The style sheet must
-  // implement the nsICSSStyleSheet interface
+  // implement the nsICSSStyleSheet interface.  Null can be passed in to clear
+  // out an existing stylesheet reference.
   NS_IMETHOD SetStyleSheet(nsICSSStyleSheet* aSheet) = 0;
 
   // Set whether or not tags & classes are case sensitive or uppercased
@@ -87,16 +88,27 @@ public:
   NS_IMETHOD SetChildLoader(nsICSSLoader* aChildLoader) = 0;
 
   /**
+   * Parse aInput into the stylesheet that was previously set by calling
+   * SetStyleSheet.  Calling this method without calling SetStyleSheet first is
+   * an error.
+   *
+   * @param aInput the data to parse
+   * @param aSheetURL the URI to use as the sheet URI (for error reporting).
+   *                  This must match the URI of the sheet passed to
+   *                  SetStyleSheet.
+   * @param aBaseURI the URI to use for relative URI resolution
+   * @param aSheetPrincipal the principal of the stylesheet.  This must match
+   *                        the principal of the sheet passed to SetStyleSheet.
+   * @param aLineNumber the line number of the first line of the sheet.   
    * @param aAllowUnsafeRules see aEnableUnsafeRules in
-   * nsICSSLoader::LoadSheetSync
+   *                          nsICSSLoader::LoadSheetSync
    */
   NS_IMETHOD Parse(nsIUnicharInputStream* aInput,
                    nsIURI*                aSheetURL,
                    nsIURI*                aBaseURI,
                    nsIPrincipal*          aSheetPrincipal,
                    PRUint32               aLineNumber,
-                   PRBool                 aAllowUnsafeRules,
-                   nsICSSStyleSheet*&     aResult) = 0;
+                   PRBool                 aAllowUnsafeRules) = 0;
 
   // Parse HTML style attribute or its equivalent in other markup
   // languages.  aBaseURL is the base url to use for relative links in