[PATCH] user32/text: Stop crash when Tab Length is zero

[Alistair Leslie-Hughes]

Signed-off-by: Alistair Leslie-Hughes <leslie_alistair at hotmail.com>
---
 dlls/user32/tests/text.c | 12 ++++++++++++
 dlls/user32/text.c       |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/dlls/user32/tests/text.c b/dlls/user32/tests/text.c
index df8d3ee..5827f64 100644
--- a/dlls/user32/tests/text.c
+++ b/dlls/user32/tests/text.c
@@ -44,6 +44,7 @@ static void test_DrawTextCalcRect(void)
     static WCHAR emptystringW[] = { 0 };
     static CHAR wordbreak_text[] = "line1 line2";
     static WCHAR wordbreak_textW[] = {'l','i','n','e','1',' ','l','i','n','e','2',0};
+    static char tabstring[] = "one\ttwo";
     INT textlen, textheight, heightcheck;
     RECT rect = { 0, 0, 100, 0 };
     BOOL ret;
@@ -580,6 +581,17 @@ static void test_DrawTextCalcRect(void)
     ok(textheight >= heightcheck * 6, "Got unexpected textheight %d, expected at least %d.\n",
        textheight, heightcheck * 6);
 
+    /* DT_TABSTOP | DT_EXPANDTABS tests */
+    textheight = DrawTextA(hdc, tabstring, -1, &rect, DT_TABSTOP | DT_EXPANDTABS);
+    ok(textheight >= heightcheck, "Got unexpected textheight %d, expected at least %d.\n",
+       textheight, heightcheck);
+
+    memset(&dtp, 0, sizeof(dtp));
+    dtp.cbSize = sizeof(dtp);
+    textheight = DrawTextExA(hdc, tabstring, -1, &rect, DT_TABSTOP | DT_EXPANDTABS, &dtp);
+    ok(textheight >= heightcheck, "Got unexpected textheight %d, expected at least %d.\n",
+       textheight, heightcheck);
+
     SelectObject(hdc, hOldFont);
     ret = DeleteObject(hFont);
     ok( ret, "DeleteObject error %u\n", GetLastError());
diff --git a/dlls/user32/text.c b/dlls/user32/text.c
index 7b0302e..2ac3afd 100644
--- a/dlls/user32/text.c
+++ b/dlls/user32/text.c
@@ -948,7 +948,7 @@ INT WINAPI DrawTextExW( HDC hdc, LPWSTR str, INT i_count,
 
     if (flags & DT_EXPANDTABS)
     {
-        int tabstop = ((flags & DT_TABSTOP) && dtp) ? dtp->iTabLength : 8;
+        int tabstop = ((flags & DT_TABSTOP) && dtp && dtp->iTabLength) ? dtp->iTabLength : 8;
 	tabwidth = tm.tmAveCharWidth * tabstop;
     }
 
-- 
1.9.1