[PATCH v6 0/1] MR2941: Prevent NULL pointer in editor_ensure_visible when retrieving row from cursor.

[Santino Mazza (＠tati1454)]

This is to prevent NULL pointers when creating a TextService with no rows in it.
This NULL pointers doesn't happen when creating a richedit windows, because
it sets an empty text when the richedit window procedure handles the WM_CREATE event.

--
  v6: riched20: Call ME_UpdateRepaint instead of editor_ensure_visible in set_selection.

https://gitlab.winehq.org/wine/wine/-/merge_requests/2941

[PATCH v6 1/1] riched20: Call ME_UpdateRepaint instead of editor_ensure_visible in set_selection.

[Santino Mazza]

From: Santino Mazza

To prevent cases where ME_WrapMarkedParagraphs has not been called causing a NULL
pointer when editor_ensure_visible tries to get the row from the cursor.
---
 dlls/riched20/editor.c       |  2 +-
 dlls/riched20/tests/txtsrv.c | 57 +++++++++++++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/dlls/riched20/editor.c b/dlls/riched20/editor.c
index 412648d9116..8ac71379533 100644
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -2150,7 +2150,7 @@ int set_selection( ME_TextEditor *editor, int to, int from )

if (!editor->bHideSelection) ME_InvalidateSelection( editor );
     end = set_selection_cursors( editor, to, from );
-    editor_ensure_visible( editor, &editor->pCursors[0] );
+    ME_UpdateRepaint( editor, FALSE );
     if (!editor->bHideSelection) ME_InvalidateSelection( editor );
     update_caret( editor );
     ME_SendSelChange( editor );
diff --git a/dlls/riched20/tests/txtsrv.c b/dlls/riched20/tests/txtsrv.c
index d75db465ce4..c602bbe94f4 100644
--- a/dlls/riched20/tests/txtsrv.c
+++ b/dlls/riched20/tests/txtsrv.c
@@ -38,6 +38,27 @@
 #include <oleauto.h>
 #include <limits.h>

+#define DEFINE_EXPECT(func) \
+    static UINT called_count_ ## func = 0
+
+#define INCREASE_CALL_COUNTER(func) \
+    do { \
+        called_count_ ## func++;     \
+    }while(0)
+
+#define CHECK_CALLED(func) \
+    do { \
+        ok(called_count_ ## func, "expected " #func "\n"); \
+    }while(0)
+
+#define CHECK_NOT_CALLED(func) \
+    do { \
+        ok(!called_count_ ## func, "unexpected " #func "\n"); \
+    }while(0)
+
+#define CLEAR_COUNTER(func) \
+    called_count_ ## func = 0
+
 static HMODULE hmoduleRichEdit;
 static IID *pIID_ITextServices;
 static IID *pIID_ITextHost;
@@ -81,6 +102,8 @@ static ITextServicesVtbl itextServicesStdcallVtbl;
 /************************************************************************/
 /* ITextHost implementation for conformance testing. */

+DEFINE_EXPECT(ITextHostImpl_TxViewChange);
+
 typedef struct ITextHostTestImpl
 {
     ITextHost ITextHost_iface;
@@ -198,6 +221,7 @@ static void __thiscall ITextHostImpl_TxViewChange(ITextHost *iface, BOOL fUpdate
     ITextHostTestImpl *This = impl_from_ITextHost(iface);
     TRACECALL("Call to TxViewChange(%p, fUpdate=%d)\n",
                This, fUpdate);
+    INCREASE_CALL_COUNTER(ITextHostImpl_TxViewChange);
 }

static BOOL __thiscall ITextHostImpl_TxCreateCaret(ITextHost *iface, HBITMAP hbmp, INT xWidth, INT yHeight)
@@ -620,7 +644,7 @@ static BOOL init_texthost(ITextServices **txtserv, ITextHost **ret)
     memset(&dummyTextHost->char_format, 0, sizeof(dummyTextHost->char_format));
     dummyTextHost->char_format.cbSize = sizeof(dummyTextHost->char_format);
     dummyTextHost->char_format.dwMask = CFM_ALL2;
-    dummyTextHost->scrollbars = 0;
+    dummyTextHost->scrollbars = ES_AUTOVSCROLL;
     dummyTextHost->props = 0;
     hf = GetStockObject(DEFAULT_GUI_FONT);
     hf_to_cf(hf, &dummyTextHost->char_format);
@@ -1240,6 +1264,36 @@ static void test_notifications( void )
     ITextHost_Release( host );
 }

+static void test_set_selection_message( void )
+{
+    ITextServices *txtserv;
+    ITextHost *host;
+    ITextHostTestImpl *host_impl;
+    LRESULT result;
+    HRESULT hr;
+
+    if (!init_texthost(&txtserv, &host))
+        return;
+
+    host_impl = impl_from_ITextHost( host );
+
+    CLEAR_COUNTER(ITextHostImpl_TxViewChange);
+    hr = ITextServices_TxSendMessage(txtserv, EM_SETSEL, 0, 20, &result);
+    ok( hr == S_OK, "got %08lx\n", hr );
+    CHECK_CALLED(ITextHostImpl_TxViewChange);
+
+    ITextServices_TxSetText(txtserv, lorem);
+    CHECK_CALLED(ITextHostImpl_TxViewChange);
+
+    CLEAR_COUNTER(ITextHostImpl_TxViewChange);
+    hr = ITextServices_TxSendMessage(txtserv, EM_SETSEL, 0, 20, &result);
+    ok( hr == S_OK, "got %08lx\n", hr );
+    CHECK_CALLED(ITextHostImpl_TxViewChange);
+
+    ITextServices_Release( txtserv );
+    ITextHost_Release( host );
+}
+
 START_TEST( txtsrv )
 {
     ITextServices *txtserv;
@@ -1273,6 +1327,7 @@ START_TEST( txtsrv )
         test_default_format();
         test_TxGetScroll();
         test_notifications();
+        test_set_selection_message();
     }
     if (wrapperCodeMem) VirtualFree(wrapperCodeMem, 0, MEM_RELEASE);
 }