[PATCH v23 2/4] comctl32: Rewrite COMCTL32_array_reserve (was PAGER_AdjustBuffer).

[Alanas Tebuev]

From: Alanas Tebuev

• Support item size that is not 2 bytes.
• Multiplication by item_size happens inside COMCTL32_array_reserve.
• Use DWORD instead of INT for *size for consistency with Alloc and negative buffer size doesn't make sense.
• Don't forget old *array when ReAlloc returns NULL.
---
 dlls/comctl32/comctl32.h |  4 ++++
 dlls/comctl32/commctrl.c | 22 ++++++++++++++++++++++
 dlls/comctl32/pager.c    | 23 +++++------------------
 3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/dlls/comctl32/comctl32.h b/dlls/comctl32/comctl32.h
index f44b4ae132f..c8671de3ea1 100644
--- a/dlls/comctl32/comctl32.h
+++ b/dlls/comctl32/comctl32.h
@@ -216,6 +216,10 @@ typedef struct
    int running;
 } SUBCLASS_INFO, *LPSUBCLASS_INFO;

+/* WM_NOTIFY unicode to ansi conversion and forwarding stuff */
+
+BOOL COMCTL32_array_reserve(void **array, DWORD *size, DWORD count, DWORD item_size);
+
 /* undocumented functions */

BOOL   WINAPI Free (LPVOID);
diff --git a/dlls/comctl32/commctrl.c b/dlls/comctl32/commctrl.c
index d87e63e813e..e3700df6e3b 100644
--- a/dlls/comctl32/commctrl.c
+++ b/dlls/comctl32/commctrl.c
@@ -2691,3 +2691,25 @@ LRESULT WINAPI SendNotifyEx(HWND hwndTo, HWND hwndFrom, UINT code, NMHDR *hdr, D

return DoNotify(&notify, code, hdr);
 }
+
+/* reallocate *array if needed so it can hold at least count items */
+/* *size measured in bytes, count measured in items */
+/* return FALSE means failed (*array still valid but too small) */
+/* return TRUE means successful */
+BOOL COMCTL32_array_reserve(void **array, DWORD *size, DWORD count, DWORD item_size)
+{
+    void *new_array;
+    DWORD needed_size;
+
+    if (count > (DWORD)-1 / item_size)
+        return FALSE;
+    needed_size = count * item_size;
+    if (*size >= needed_size)
+        return TRUE;
+    new_array = *array ? ReAlloc(*array, needed_size) : Alloc(needed_size);
+    if (!new_array)
+        return FALSE;
+    *array = new_array;
+    *size = needed_size;
+    return TRUE;
+}
diff --git a/dlls/comctl32/pager.c b/dlls/comctl32/pager.c
index 07484c6ebf5..875beef0d8b 100644
--- a/dlls/comctl32/pager.c
+++ b/dlls/comctl32/pager.c
@@ -85,7 +85,7 @@ typedef struct
     INT    BRbtnState; /* state of bottom or right btn */
     INT    direction;  /* direction of the scroll, (e.g. PGF_SCROLLUP) */
     WCHAR  *pwszBuffer;/* text buffer for converted notifications */
-    INT    nBufferSize;/* size of the above buffer */
+    DWORD  nBufferSize;/* size of the above buffer measured in bytes */
 } PAGER_INFO;

#define TIMERID1         1
@@ -1096,19 +1096,6 @@ static UINT PAGER_GetAnsiNtfCode(UINT code)
     return code;
 }

-static BOOL PAGER_AdjustBuffer(PAGER_INFO *infoPtr, INT size)
-{
-    if (!infoPtr->pwszBuffer)
-        infoPtr->pwszBuffer = Alloc(size);
-    else if (infoPtr->nBufferSize < size)
-        infoPtr->pwszBuffer = ReAlloc(infoPtr->pwszBuffer, size);
-
-    if (!infoPtr->pwszBuffer) return FALSE;
-    if (infoPtr->nBufferSize < size) infoPtr->nBufferSize = size;
-
-    return TRUE;
-}
-
 /* Convert text to Unicode and return the original text address */
 static WCHAR *PAGER_ConvertText(WCHAR **text)
 {
@@ -1229,7 +1216,7 @@ static LRESULT PAGER_Notify(PAGER_INFO *infoPtr, NMHDR *hdr)
     {
         NMDATETIMEFORMATW *nmdtf = (NMDATETIMEFORMATW *)hdr;
         WCHAR *oldFormat;
-        INT textLength;
+        DWORD textLength;

hdr->code = PAGER_GetAnsiNtfCode(hdr->code);
         oldFormat = PAGER_ConvertText((WCHAR **)&nmdtf->pszFormat);
@@ -1239,7 +1226,7 @@ static LRESULT PAGER_Notify(PAGER_INFO *infoPtr, NMHDR *hdr)
         if (nmdtf->pszDisplay)
         {
             textLength = MultiByteToWideChar(CP_ACP, 0, (LPCSTR)nmdtf->pszDisplay, -1, 0, 0);
-            if (!PAGER_AdjustBuffer(infoPtr, textLength * sizeof(WCHAR))) return ret;
+            if (!COMCTL32_array_reserve((void **)&infoPtr->pwszBuffer, &infoPtr->nBufferSize, textLength, sizeof(WCHAR))) return ret;
             MultiByteToWideChar(CP_ACP, 0, (LPCSTR)nmdtf->pszDisplay, -1, infoPtr->pwszBuffer, textLength);
             if (nmdtf->pszDisplay != nmdtf->szDisplay)
                 nmdtf->pszDisplay = infoPtr->pwszBuffer;
@@ -1346,7 +1333,7 @@ static LRESULT PAGER_Notify(PAGER_INFO *infoPtr, NMHDR *hdr)
     {
         NMTTDISPINFOW *nmttdiW = (NMTTDISPINFOW *)hdr;
         NMTTDISPINFOA nmttdiA = {{0}};
-        INT size;
+        DWORD size;

nmttdiA.hdr.code = PAGER_GetAnsiNtfCode(nmttdiW->hdr.code);
         nmttdiA.hdr.hwndFrom = nmttdiW->hdr.hwndFrom;
@@ -1373,7 +1360,7 @@ static LRESULT PAGER_Notify(PAGER_INFO *infoPtr, NMHDR *hdr)
             size = MultiByteToWideChar(CP_ACP, 0, nmttdiA.lpszText, -1, 0, 0);
             if (size > ARRAY_SIZE(nmttdiW->szText))
             {
-                if (!PAGER_AdjustBuffer(infoPtr, size * sizeof(WCHAR))) return ret;
+                if (!COMCTL32_array_reserve((void **)&infoPtr->pwszBuffer, &infoPtr->nBufferSize, size, sizeof(WCHAR))) return ret;
                 MultiByteToWideChar(CP_ACP, 0, nmttdiA.lpszText, -1, infoPtr->pwszBuffer, size);
                 nmttdiW->lpszText = infoPtr->pwszBuffer;
                 /* Override content in szText */