[reactos] 01/01: [IMM32] Improve IchWideFromAnsi and IchAnsiFromWide (#4028)

[Katayama Hirofumi MZ]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=fec35dc89386eb02761b5e...

commit fec35dc89386eb02761b5e12573de164fb5904c9
Author:     Katayama Hirofumi MZ [e-mail]
AuthorDate: Fri Oct 15 10:31:08 2021 +0900
Commit:     GitHub [e-mail]
CommitDate: Fri Oct 15 10:31:08 2021 +0900

[IMM32] Improve IchWideFromAnsi and IchAnsiFromWide (#4028)

- Use LONG instead of DWORD for indexing and counting the characters.
    - Use the sign for the loop condition.
    - Add NUL check.
    CORE-11700
---
 dll/win32/imm32/precomp.h |  4 ++--
 dll/win32/imm32/utils.c   | 28 +++++++++++-----------------
 2 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/dll/win32/imm32/precomp.h b/dll/win32/imm32/precomp.h
index 17f46493c88..35d03332835 100644
--- a/dll/win32/imm32/precomp.h
+++ b/dll/win32/imm32/precomp.h
@@ -81,8 +81,8 @@ LPVOID APIENTRY Imm32HeapAlloc(DWORD dwFlags, DWORD dwBytes);

LPWSTR APIENTRY Imm32WideFromAnsi(LPCSTR pszA);
 LPSTR APIENTRY Imm32AnsiFromWide(LPCWSTR pszW);
-DWORD APIENTRY IchWideFromAnsi(DWORD cchAnsi, LPCSTR pchAnsi, UINT uCodePage);
-DWORD APIENTRY IchAnsiFromWide(DWORD cchWide, LPCWSTR pchWide, UINT uCodePage);
+LONG APIENTRY IchWideFromAnsi(LONG cchAnsi, LPCSTR pchAnsi, UINT uCodePage);
+LONG APIENTRY IchAnsiFromWide(LONG cchWide, LPCWSTR pchWide, UINT uCodePage);
 PIMEDPI APIENTRY ImmLockOrLoadImeDpi(HKL hKL);
 LPINPUTCONTEXT APIENTRY Imm32LockIMCEx(HIMC hIMC, BOOL fSelect);
 BOOL APIENTRY Imm32ReleaseIME(HKL hKL);
diff --git a/dll/win32/imm32/utils.c b/dll/win32/imm32/utils.c
index 20790f78110..6dddd9df22a 100644
--- a/dll/win32/imm32/utils.c
+++ b/dll/win32/imm32/utils.c
@@ -50,23 +50,16 @@ LPSTR APIENTRY Imm32AnsiFromWide(LPCWSTR pszW)
     return pszA;
 }

-DWORD APIENTRY IchWideFromAnsi(DWORD cchAnsi, LPCSTR pchAnsi, UINT uCodePage)
+/* Converts the character index */
+LONG APIENTRY IchWideFromAnsi(LONG cchAnsi, LPCSTR pchAnsi, UINT uCodePage)
 {
-    DWORD cchWide;
-    for (cchWide = 0; cchAnsi; ++cchWide)
+    LONG cchWide;
+    for (cchWide = 0; cchAnsi > 0; ++cchWide)
     {
-        if (IsDBCSLeadByteEx(uCodePage, *pchAnsi))
+        if (IsDBCSLeadByteEx(uCodePage, *pchAnsi) && pchAnsi[1])
         {
-            if (cchAnsi <= 1)
-            {
-                ++cchWide;
-                break;
-            }
-            else
-            {
-                cchAnsi -= 2;
-                pchAnsi += 2;
-            }
+            cchAnsi -= 2;
+            pchAnsi += 2;
         }
         else
         {
@@ -77,10 +70,11 @@ DWORD APIENTRY IchWideFromAnsi(DWORD cchAnsi, LPCSTR pchAnsi, UINT uCodePage)
     return cchWide;
 }

-DWORD APIENTRY IchAnsiFromWide(DWORD cchWide, LPCWSTR pchWide, UINT uCodePage)
+/* Converts the character index */
+LONG APIENTRY IchAnsiFromWide(LONG cchWide, LPCWSTR pchWide, UINT uCodePage)
 {
-    DWORD cb, cchAnsi;
-    for (cchAnsi = 0; cchWide; ++cchAnsi, ++pchWide, --cchWide)
+    LONG cb, cchAnsi;
+    for (cchAnsi = 0; cchWide > 0; ++cchAnsi, ++pchWide, --cchWide)
     {
         cb = WideCharToMultiByte(uCodePage, 0, pchWide, 1, NULL, 0, NULL, NULL);
         if (cb > 1)