Fix behaviour of app.alert() with a single object argument.

Centralize the "arguments in an object" logic.  See the section
"Method Arguments" in the js_api_reference.pdf.  Add some tests
to hit the ambiguous cases this section implies, and test that
all parameters are passed end-to-end to our callbacks.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1641693003 .

3 files changed, 80 insertions, 75 deletions

diff --git a/fpdfsdk/src/javascript/JS_Value.cpp b/fpdfsdk/src/javascript/JS_Value.cpp
index cfa565e4d4..c63963a110 100644
--- a/fpdfsdk/src/javascript/JS_Value.cpp
+++ b/fpdfsdk/src/javascript/JS_Value.cpp
@@ -7,6 +7,7 @@
 #include "JS_Value.h"
 
 #include <time.h>
+#include <algorithm>
 #include <cmath>
 #include <limits>
 
@@ -879,3 +880,35 @@ bool JS_PortIsNan(double d) {
 double JS_LocalTime(double d) {
   return JS_GetDateTime() + _getDaylightSavingTA(d);
 }
+
+std::vector<CJS_Value> JS_ExpandKeywordParams(
+    CJS_Runtime* pRuntime,
+    const std::vector<CJS_Value>& originals,
+    size_t nKeywords,
+    ...) {
+  ASSERT(nKeywords);
+
+  std::vector<CJS_Value> result(nKeywords, CJS_Value(pRuntime));
+  size_t size = std::min(originals.size(), nKeywords);
+  for (size_t i = 0; i < size; ++i)
+    result[i] = originals[i];
+
+  if (originals.size() != 1 || originals[0].GetType() != CJS_Value::VT_object ||
+      originals[0].IsArrayObject()) {
+    return result;
+  }
+  v8::Local<v8::Object> pObj = originals[0].ToV8Object();
+  result[0] = CJS_Value(pRuntime);  // Make unknown.
+
+  va_list ap;
+  va_start(ap, nKeywords);
+  for (int i = 0; i < nKeywords; ++i) {
+    const wchar_t* property = va_arg(ap, const wchar_t*);
+    v8::Local<v8::Value> v8Value =
+        FXJS_GetObjectElement(pRuntime->GetIsolate(), pObj, property);
+    if (!v8Value->IsUndefined())
+      result[i] = CJS_Value(pRuntime, v8Value, CJS_Value::VT_unknown);
+  }
+  va_end(ap);
+  return result;
+}
diff --git a/fpdfsdk/src/javascript/JS_Value.h b/fpdfsdk/src/javascript/JS_Value.h
index 20a6e38b46..c33a973a12 100644
--- a/fpdfsdk/src/javascript/JS_Value.h
+++ b/fpdfsdk/src/javascript/JS_Value.h
@@ -213,4 +213,16 @@ double JS_MakeDate(double day, double time);
 bool JS_PortIsNan(double d);
 double JS_LocalTime(double d);
 
+// Some JS methods have the bizarre convention that they may also be called
+// with a single argument which is an object containing the actual arguments
+// as its properties. The varying arguments to this method are the property
+// names as wchar_t string literals corresponding to each positional argument.
+// The result will always contain |nKeywords| value, with unspecified ones
+// being set to type VT_unknown.
+std::vector<CJS_Value> JS_ExpandKeywordParams(
+    CJS_Runtime* pRuntime,
+    const std::vector<CJS_Value>& originals,
+    size_t nKeywords,
+    ...);
+
 #endif  // FPDFSDK_SRC_JAVASCRIPT_JS_VALUE_H_
diff --git a/fpdfsdk/src/javascript/app.cpp b/fpdfsdk/src/javascript/app.cpp
index 5959b9a1b5..d8be575918 100644
--- a/fpdfsdk/src/javascript/app.cpp
+++ b/fpdfsdk/src/javascript/app.cpp
@@ -246,90 +246,50 @@ FX_BOOL app::alert(IJS_Context* cc,
                    const std::vector<CJS_Value>& params,
                    CJS_Value& vRet,
                    CFX_WideString& sError) {
-  int iSize = params.size();
-  if (iSize < 1)
-    return FALSE;
-
-  CFX_WideString swMsg = L"";
-  CFX_WideString swTitle = L"";
-  int iIcon = 0;
-  int iType = 0;
-
+  CJS_Context* pContext = static_cast<CJS_Context*>(cc);
   CJS_Runtime* pRuntime = CJS_Runtime::FromContext(cc);
-  v8::Isolate* isolate = pRuntime->GetIsolate();
+  std::vector<CJS_Value> newParams = JS_ExpandKeywordParams(
+      pRuntime, params, 4, L"cMsg", L"nIcon", L"nType", L"cTitle");
 
-  if (iSize == 1) {
-    if (params[0].GetType() == CJS_Value::VT_object) {
-      v8::Local<v8::Object> pObj = params[0].ToV8Object();
-      {
-        v8::Local<v8::Value> pValue =
-            FXJS_GetObjectElement(isolate, pObj, L"cMsg");
-        swMsg = CJS_Value(pRuntime, pValue, CJS_Value::VT_unknown)
-                    .ToCFXWideString();
-
-        pValue = FXJS_GetObjectElement(isolate, pObj, L"cTitle");
-        swTitle = CJS_Value(pRuntime, pValue, CJS_Value::VT_unknown)
-                      .ToCFXWideString();
-
-        pValue = FXJS_GetObjectElement(isolate, pObj, L"nIcon");
-        iIcon = CJS_Value(pRuntime, pValue, CJS_Value::VT_unknown).ToInt();
-
-        pValue = FXJS_GetObjectElement(isolate, pObj, L"nType");
-        iType = CJS_Value(pRuntime, pValue, CJS_Value::VT_unknown).ToInt();
-      }
-
-      if (swMsg == L"") {
-        CJS_Array carray(pRuntime);
-        if (params[0].ConvertToArray(carray)) {
-          int iLength = carray.GetLength();
-          CJS_Value* pValue = new CJS_Value(pRuntime);
-          for (int i = 0; i < iLength; ++i) {
-            carray.GetElement(i, *pValue);
-            swMsg += (*pValue).ToCFXWideString();
-            if (i < iLength - 1)
-              swMsg += L",  ";
-          }
+  if (newParams[0].GetType() == CJS_Value::VT_unknown) {
+    sError = JSGetStringFromID(pContext, IDS_STRING_JSPARAMERROR);
+    return FALSE;
+  }
 
-          delete pValue;
-        }
+  CFX_WideString swMsg;
+  if (newParams[0].GetType() == CJS_Value::VT_object) {
+    CJS_Array carray(pRuntime);
+    if (newParams[0].ConvertToArray(carray)) {
+      swMsg = L"[";
+      CJS_Value element(pRuntime);
+      for (int i = 0; i < carray.GetLength(); ++i) {
+        if (i)
+          swMsg += L", ";
+        carray.GetElement(i, element);
+        swMsg += element.ToCFXWideString();
       }
-
-      if (swTitle == L"")
-        swTitle = JSGetStringFromID((CJS_Context*)cc, IDS_STRING_JSALERT);
-    } else if (params[0].GetType() == CJS_Value::VT_boolean) {
-      FX_BOOL bGet = params[0].ToBool();
-      if (bGet)
-        swMsg = L"true";
-      else
-        swMsg = L"false";
-
-      swTitle = JSGetStringFromID((CJS_Context*)cc, IDS_STRING_JSALERT);
+      swMsg += L"]";
     } else {
-      swMsg = params[0].ToCFXWideString();
-      swTitle = JSGetStringFromID((CJS_Context*)cc, IDS_STRING_JSALERT);
+      swMsg = newParams[0].ToCFXWideString();
     }
   } else {
-    if (params[0].GetType() == CJS_Value::VT_boolean) {
-      FX_BOOL bGet = params[0].ToBool();
-      if (bGet)
-        swMsg = L"true";
-      else
-        swMsg = L"false";
-    } else {
-      swMsg = params[0].ToCFXWideString();
-    }
-    swTitle = JSGetStringFromID((CJS_Context*)cc, IDS_STRING_JSALERT);
-
-    for (int i = 1; i < iSize; i++) {
-      if (i == 1)
-        iIcon = params[i].ToInt();
-      if (i == 2)
-        iType = params[i].ToInt();
-      if (i == 3)
-        swTitle = params[i].ToCFXWideString();
-    }
+    swMsg = newParams[0].ToCFXWideString();
   }
 
+  int iIcon = 0;
+  if (newParams[1].GetType() != CJS_Value::VT_unknown)
+    iIcon = newParams[1].ToInt();
+
+  int iType = 0;
+  if (newParams[2].GetType() != CJS_Value::VT_unknown)
+    iType = newParams[2].ToInt();
+
+  CFX_WideString swTitle;
+  if (newParams[3].GetType() != CJS_Value::VT_unknown)
+    swTitle = newParams[3].ToCFXWideString();
+  else
+    swTitle = JSGetStringFromID(pContext, IDS_STRING_JSALERT);
+
   pRuntime->BeginBlock();
   vRet = MsgBox(pRuntime->GetReaderApp(), swMsg.c_str(), swTitle.c_str(), iType,
                 iIcon);