Fix GH-8750: Can not create VT_ERROR variant type

We add support for creating `VT_ERROR` variants via `__construct()`,
and allow casting to int via `variant_cast()` and `variant_set_type()`.
We do not, however, allow type conversion by other means, to avoid
otherwise easily introduced type confusion.  VB(A) also only allows
explicit type conversion.

We also introduce `DISP_E_PARAMNOTFOUND` which might be the most
important `scode` for this purpose, since this allows to skip optional
parameters in method calls.

Closes GH-8886.

Author: cmb69

NEWS

@@ -10,6 +10,9 @@ PHP                                                                        NEWS
     json_encode(), serialize(), iconv_*(), mb_ereg*(), session_create_id(),
     http_build_query(), strstr(), Reflection*::__toString(). (Arnaud)
 
+- COM:
+  . Fixed bug GH-8750 (Can not create VT_ERROR variant type). (cmb)
+
 - FPM:
   . Added listen.setfib pool option to set route FIB on FreeBSD. (David Carlier)
   . Added access.suppress_path pool option to filter access log entries.

UPGRADING

@@ -264,6 +264,7 @@ PHP 8.2 UPGRADE NOTES
 ========================================
 
 - COM_DOTNET:
+  . DISP_E_PARAMNOTFOUND
   . LOCALE_NEUTRAL
 
 - Curl:

ext/com_dotnet/com_extension.c

@@ -32,11 +32,13 @@
 #define PHP_DISP_E_DIVBYZERO ((zend_long) (ULONG) DISP_E_DIVBYZERO)
 #define PHP_DISP_E_OVERFLOW ((zend_long) (ULONG) DISP_E_OVERFLOW)
 #define PHP_DISP_E_BADINDEX ((zend_long) (ULONG) DISP_E_BADINDEX)
+#define PHP_DISP_E_PARAMNOTFOUND ((zend_long) (ULONG) DISP_E_PARAMNOTFOUND)
 #define PHP_MK_E_UNAVAILABLE ((zend_long) (ULONG) MK_E_UNAVAILABLE)
 #else
 #define PHP_DISP_E_DIVBYZERO DISP_E_DIVBYZERO
 #define PHP_DISP_E_OVERFLOW DISP_E_OVERFLOW
 #define PHP_DISP_E_BADINDEX DISP_E_BADINDEX
+#define PHP_DISP_E_PARAMNOTFOUND DISP_E_PARAMNOTFOUND
 #define PHP_MK_E_UNAVAILABLE MK_E_UNAVAILABLE
 #endif
 

ext/com_dotnet/com_extension.stub.php

@@ -264,6 +264,11 @@
  * @cname PHP_DISP_E_BADINDEX
  */
 const DISP_E_BADINDEX = UNKNOWN;
+/**
+ * @var int
+ * @cname PHP_DISP_E_PARAMNOTFOUND
+ */
+const DISP_E_PARAMNOTFOUND = UNKNOWN;
 /**
  * @var int
  * @cname PHP_MK_E_UNAVAILABLE

ext/com_dotnet/com_extension_arginfo.h

@@ -92,7 +92,7 @@ static void safe_array_from_zval(VARIANT *v, zval *z, int codepage)
 	}
 }
 
-PHP_COM_DOTNET_API void php_com_variant_from_zval(VARIANT *v, zval *z, int codepage)
+static void php_com_variant_from_zval_ex(VARIANT *v, zval *z, int codepage, VARTYPE vt)
 {
 	php_com_dotnet_object *obj;
 	zend_uchar ztype = IS_NULL;
@@ -145,6 +145,11 @@ PHP_COM_DOTNET_API void php_com_variant_from_zval(VARIANT *v, zval *z, int codep
 			break;
 
 		case IS_LONG:
+			if (vt == VT_ERROR) {
+				V_VT(v) = VT_ERROR;
+				V_ERROR(v) = Z_LVAL_P(z);
+				break;
+			}
 #if SIZEOF_ZEND_LONG == 4
 			V_VT(v) = VT_I4;
 			V_I4(v) = Z_LVAL_P(z);
@@ -172,6 +177,11 @@ PHP_COM_DOTNET_API void php_com_variant_from_zval(VARIANT *v, zval *z, int codep
 	}
 }
 
+PHP_COM_DOTNET_API void php_com_variant_from_zval(VARIANT *v, zval *z, int codepage)
+{
+	php_com_variant_from_zval_ex(v, z, codepage, VT_EMPTY);
+}
+
 PHP_COM_DOTNET_API zend_result php_com_zval_from_variant(zval *z, VARIANT *v, int codepage)
 {
 	OLECHAR *olestring = NULL;
@@ -448,7 +458,7 @@ PHP_METHOD(variant, __construct)
 	}
 
 	if (zvalue) {
-		php_com_variant_from_zval(&obj->v, zvalue, obj->code_page);
+		php_com_variant_from_zval_ex(&obj->v, zvalue, obj->code_page, vt);
 	}
 
 	/* Only perform conversion if variant not already of type passed */
@@ -1019,6 +1029,7 @@ PHP_FUNCTION(variant_set_type)
 	zval *zobj;
 	php_com_dotnet_object *obj;
 	/* VARTYPE == unsigned short */ zend_long vt;
+	VARIANT vtmp;
 	HRESULT res;
 
 	if (FAILURE == zend_parse_parameters(ZEND_NUM_ARGS(),
@@ -1027,7 +1038,12 @@ PHP_FUNCTION(variant_set_type)
 	}
 	obj = CDNO_FETCH(zobj);
 
-	res = VariantChangeType(&obj->v, &obj->v, 0, (VARTYPE)vt);
+	if (V_VT(&obj->v) == VT_ERROR) {
+		VariantInit(&vtmp);
+		V_VT(&vtmp) = VT_I4;
+		V_I4(&vtmp) = V_ERROR(&obj->v);
+	}
+	res = VariantChangeType(&obj->v, V_VT(&obj->v) != VT_ERROR ? &obj->v : &vtmp, 0, (VARTYPE)vt);
 
 	if (SUCCEEDED(res)) {
 		if (vt != VT_DISPATCH && obj->typeinfo) {
@@ -1063,7 +1079,11 @@ PHP_FUNCTION(variant_cast)
 	obj = CDNO_FETCH(zobj);
 
 	VariantInit(&vres);
-	res = VariantChangeType(&vres, &obj->v, 0, (VARTYPE)vt);
+	if (V_VT(&obj->v) == VT_ERROR) {
+		V_VT(&vres) = VT_I4;
+		V_I4(&vres) = V_ERROR(&obj->v);
+	}
+	res = VariantChangeType(&vres, V_VT(&vres) == VT_EMPTY ? &obj->v : &vres, 0, (VARTYPE)vt);
 
 	if (SUCCEEDED(res)) {
 		php_com_wrap_variant(return_value, &vres, obj->code_page);

ext/com_dotnet/com_variant.c

@@ -0,0 +1,47 @@
+--TEST--
+Bug GH-8750 (Can not create VT_ERROR variant type)
+--EXTENSIONS--
+com_dotnet
+--SKIPIF--
+<?php
+$provider = "Microsoft.ACE.OLEDB.12.0";
+$filename = __DIR__ . "\\gh8750.mdb";
+$catalog = new com("ADOX.Catalog");
+try {
+    $catalog->Create("Provider=$provider;Data Source=$filename");
+} catch (com_exception) {
+    die("skip $provider provider not available");
+}
+$catalog = null;
+@unlink($filename);
+?>
+--FILE--
+<?php
+$filename = __DIR__ . "\\gh8750.mdb";
+
+$catalog = new com("ADOX.Catalog");
+$catalog->Create("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=$filename");
+$catalog = null;
+
+$db = new com("ADODB.Connection");
+$db->ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=$filename";
+$db->Mode = 1; // adModeRead
+$db->Open();
+// adSchemaProviderSpecific, *missing*, JET_SCHEMA_USERROSTER
+$rs = $db->OpenSchema(-1, new variant(DISP_E_PARAMNOTFOUND, VT_ERROR), "{947bb102-5d43-11d1-bdbf-00c04fb92675}");
+// manual counting since rs.RecordCount is -1 (not supported)
+$i = 0;
+while (!$rs->EOF) {
+    $rs->MoveNext();
+    $i++;
+}
+$rs->Close();
+$db->Close();
+var_dump($i);
+?>
+--EXPECT--
+int(1)
+--CLEAN--
+<?php
+unlink(__DIR__ . "/gh8750.mdb");
+?>

ext/com_dotnet/tests/gh8750.phpt

@@ -0,0 +1,36 @@
+--TEST--
+Bug GH-8750 (Can not create VT_ERROR variant type) - cast and conversion
+--EXTENSIONS--
+com_dotnet
+--FILE--
+<?php
+$error = new variant(DISP_E_PARAMNOTFOUND, VT_ERROR);
+
+// explicit variant_cast() to int is supported if in range
+echo variant_cast($error, VT_I4), PHP_EOL;
+
+// however, explicit (int) casts are not supported
+echo (int) $error, PHP_EOL;
+
+// nor are implicit conversions
+try {
+    echo 1 + $error, PHP_EOL;
+} catch (TypeError $err) {
+    echo $err->getMessage(), PHP_EOL;
+}
+
+// we can retrieve the type
+echo variant_get_type($error), PHP_EOL;
+
+// and change it via variant_set_type()
+variant_set_type($error, VT_I4);
+echo variant_get_type($error), PHP_EOL;
+?>
+--EXPECTF--
+-2147352572
+
+Warning: Object of class variant could not be converted to int in %s on line %d
+1
+Unsupported operand types: int + variant
+10
+3