[cfinck] 74323: [SPOOLSS] Add ASSERTs, improve documentation and the variety of tests for AlignRpcPtr/UndoAlignRpcPtr. Based on comments by Serge Gautherie.

Author: cfinck
Date: Sun Apr 16 10:36:16 2017
New Revision: 74323

URL: http://svn.reactos.org/svn/reactos?rev=74323&view=rev
Log:
[SPOOLSS]
Add ASSERTs, improve documentation and the variety of tests for
AlignRpcPtr/UndoAlignRpcPtr.
Based on comments by Serge Gautherie.

Modified:
    trunk/reactos/win32ss/printing/base/spoolss/memory.c
    trunk/rostests/apitests/spoolss/AlignRpcPtr.c

Modified: trunk/reactos/win32ss/printing/base/spoolss/memory.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/win32ss/printing/base/spoo…
==============================================================================
--- trunk/reactos/win32ss/printing/base/spoolss/memory.c	[iso-8859-1] (original)
+++ trunk/reactos/win32ss/printing/base/spoolss/memory.c	[iso-8859-1] Sun Apr 16 10:36:16
2017
@@ -28,6 +28,8 @@
 PVOID WINAPI
 AlignRpcPtr(PVOID pBuffer, PDWORD pcbBuffer)
 {
+    ASSERT(pcbBuffer);
+
     // Align down the buffer size in pcbBuffer to a 4-byte boundary.
     *pcbBuffer -= *pcbBuffer % sizeof(DWORD);
 
@@ -209,7 +211,7 @@
  * The original unaligned buffer, which you input as pBuffer to AlignRpcPtr.
  * The data from pSourceBuffer is copied into this buffer before pSourceBuffer is freed.
  * If AlignRpcPtr did not allocate a buffer, pDestinationBuffer equals pSourceBuffer and
no memory is copied or freed.
- * This parameter may be NULL if pSourceBuffer is NULL.
+ * This parameter may be NULL if pSourceBuffer is NULL or cbBuffer is 0.
  *
  * @param pSourceBuffer
  * The aligned buffer, which is returned by AlignRpcPtr.
@@ -233,6 +235,9 @@
 PDWORD WINAPI
 UndoAlignRpcPtr(PVOID pDestinationBuffer, PVOID pSourceBuffer, DWORD cbBuffer, PDWORD
pcbNeeded)
 {
+    // pDestinationBuffer is accessed unless pSourceBuffer equals pDestinationBuffer or
cbBuffer is 0.
+    ASSERT(pDestinationBuffer || pSourceBuffer == pDestinationBuffer || cbBuffer == 0);
+
     // If pSourceBuffer is given, and source and destination pointers don't match,
     // we assume that pSourceBuffer is the buffer allocated by AlignRpcPtr.
     if (pSourceBuffer && pSourceBuffer != pDestinationBuffer)

Modified: trunk/rostests/apitests/spoolss/AlignRpcPtr.c
URL:
http://svn.reactos.org/svn/reactos/trunk/rostests/apitests/spoolss/AlignRpc…
==============================================================================
--- trunk/rostests/apitests/spoolss/AlignRpcPtr.c	[iso-8859-1] (original)
+++ trunk/rostests/apitests/spoolss/AlignRpcPtr.c	[iso-8859-1] Sun Apr 16 10:36:16 2017
@@ -54,13 +54,18 @@
     ok(pOutputBuffer != pInputBuffer, "pOutputBuffer == pInputBuffer\n");
     ok(cbBuffer == 4, "cbBuffer is %lu\n", cbBuffer);
 
+    // Prove that AlignRpcPtr also works with a NULL buffer. The size should be aligned
down.
+    cbBuffer = 6;
+    ok(!AlignRpcPtr(NULL, &cbBuffer), "AlignRpcPtr returns something\n");
+    ok(cbBuffer == 4, "cbBuffer is %lu\n", cbBuffer);
+
     // We can also test all parameters of UndoAlignRpcPtr here.
     // Because pOutputBuffer != pInputBuffer, it copies the given 4 bytes from (aligned)
pOutputBuffer to (unaligned) pInputBuffer
     // while aligning up the given 7 bytes in our passed &cbBuffer.
     // &cbBuffer is also returned.
     strcpy(pOutputBuffer, "abc");
     strcpy(pInputBuffer, "XXXXXXXXX");
-    cbBuffer = 7;
+    cbBuffer = 5;
     pcbBuffer = UndoAlignRpcPtr(pInputBuffer, pOutputBuffer, 4, &cbBuffer);
     ok(strcmp(pInputBuffer, "abc") == 0, "pInputBuffer is %s\n",
pInputBuffer);
     ok(pcbBuffer == &cbBuffer, "pcbBuffer != &cbBuffer\n");
@@ -68,14 +73,14 @@
 
     // Prove that UndoAlignRpcPtr works without any parameters and doesn't try to
copy data from NULL pointers.
     ok(!UndoAlignRpcPtr(NULL, NULL, 0, NULL), "UndoAlignRpcPtr returns
something\n");
-    ok(!UndoAlignRpcPtr(NULL, NULL, 4, NULL), "UndoAlignRpcPtr returns
something\n");
+    ok(!UndoAlignRpcPtr(NULL, NULL, 6, NULL), "UndoAlignRpcPtr returns
something\n");
 
     // Prove that UndoAlignRpcPtr doesn't access source and destination memory at all
when they are equal.
     // If it did, it should crash here, because I'm giving invalid memory addresses.
     ok(!UndoAlignRpcPtr((PVOID)1, (PVOID)1, 4, NULL), "UndoAlignRpcPtr returns
something\n");
 
-    // Prove that the pcbNeeded parameter of UndoAlignRpcPtr works independently and
aligns up everything up to a DWORD.
-    cbBuffer = 0xFFFFFFFF;
+    // Prove that the pcbNeeded parameter of UndoAlignRpcPtr works independently and
aligns up to a DWORD.
+    cbBuffer = 0xFFFFFFFD;
     pcbBuffer = UndoAlignRpcPtr(NULL, NULL, 0, &cbBuffer);
     ok(pcbBuffer == &cbBuffer, "pcbBuffer != &cbBuffer\n");
     ok(cbBuffer == 0, "cbBuffer is %lu\n", cbBuffer);