X-Git-Url: https://git.reactos.org/?p=reactos.git;a=blobdiff_plain;f=dll%2Fwin32%2Fmsi%2Fcond.tab.c;h=e68723db89bec285f1dc64b0c0d2aa4153376f19;hp=2b10d209be6de20a0678a23641a58e4337040c02;hb=16d979e4add671a34557b0db3df9ce70b61ccf07;hpb=c47ea5cd38cff79648f4c7642d4ea99e49bccf1b;ds=sidebyside

diff --git a/dll/win32/msi/cond.tab.c b/dll/win32/msi/cond.tab.c
index 2b10d209be6..e68723db89b 100644
--- a/dll/win32/msi/cond.tab.c
+++ b/dll/win32/msi/cond.tab.c
@@ -2329,11 +2329,21 @@ static INT compare_substring( LPCWSTR a, INT operator, LPCWSTR b )
     case COND_LHS:
     	return 0 == strncmpW( a, b, lstrlenW( b ) );
     case COND_RHS:
-    	return 0 == lstrcmpW( a + (lstrlenW( a ) - lstrlenW( b )), b );
+    {
+        int l = lstrlenW( a );
+        int r = lstrlenW( b );
+        if (r > l) return 0;
+        return 0 == lstrcmpW( a + (l - r), b );
+    }
     case COND_ILHS:
     	return 0 == strncmpiW( a, b, lstrlenW( b ) );
     case COND_IRHS:
-        return 0 == lstrcmpiW( a + (lstrlenW( a ) - lstrlenW( b )), b );
+    {
+        int l = lstrlenW( a );
+        int r = lstrlenW( b );
+        if (r > l) return 0;
+        return 0 == lstrcmpiW( a + (l - r), b );
+    }
     default:
     	ERR("invalid substring operator\n");
         return 0;