made COM_FindFile to accept both file and handle as NULL. Added

COM_FileExists as a new helper procedure which calls COM_FindFile
with both file and handle parameters as NULL.


git-svn-id: svn://svn.code.sf.net/p/quakespasm/code/trunk/quakespasm@373 af15c1b1-3010-417e-b628-4374ebc0bcbd

Quake/common.c

@@ -1451,6 +1451,8 @@ COM_FindFile
 
 Finds the file in the search path.
 Sets com_filesize and one of handle or file
+If neither of file or handle is set, this
+can be used for detecting a file's presence.
 ===========
 */
 static int COM_FindFile (const char *filename, int *handle, FILE **file,
@@ -1464,8 +1466,6 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 
 	if (file && handle)
 		Sys_Error ("COM_FindFile: both handle and file set");
-	if (!file && !handle)
-		Sys_Error ("COM_FindFile: neither handle or file set");
 
 	file_from_pak = 0;
 
@@ -1483,21 +1483,21 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 				if (!strcmp (pak->files[i].name, filename))
 				{	// found it!
 				//	Sys_Printf ("PackFile: %s : %s\n",pak->filename, filename);
+					file_from_pak = 1;
+					com_filesize = pak->files[i].filelen;
+					if (path_id)
+						*path_id = search->path_id;
 					if (handle)
 					{
 						*handle = pak->handle;
 						Sys_FileSeek (pak->handle, pak->files[i].filepos);
 					}
-					else
+					else if (file)
 					{       // open a new file on the pakfile
 						*file = fopen (pak->filename, "rb");
 						if (*file)
 							fseek (*file, pak->files[i].filepos, SEEK_SET);
 					}
-					file_from_pak = 1;
-					com_filesize = pak->files[i].filelen;
-					if (path_id)
-						*path_id = search->path_id;
 					return com_filesize;
 				}
 		}
@@ -1521,12 +1521,18 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 			if (path_id)
 				*path_id = search->path_id;
 			if (handle)
+			{
 				*handle = i;
-			else
+			}
+			else if (file)
 			{
 				Sys_FileClose (i);
 				*file = fopen (netpath, "rb");
 			}
+			else
+			{
+				Sys_FileClose (i);
+			}
 			return com_filesize;
 		}
 
@@ -1536,13 +1542,26 @@ static int COM_FindFile (const char *filename, int *handle, FILE **file,
 
 	if (handle)
 		*handle = -1;
-	else
+	else if (file)
 		*file = NULL;
 	com_filesize = -1;
 	return -1;
 }
 
 
+/*
+===========
+COM_FileExists
+
+Returns com_filesize if file is found in the quake filesystem,
+-1 if not. Closes the files it opens, if any.
+===========
+*/
+int COM_FileExists (const char *filename, unsigned int *path_id)
+{
+	return COM_FindFile (filename, NULL, NULL, path_id);
+}
+
 /*
 ===========
 COM_OpenFile

Quake/common.h

@@ -188,6 +188,7 @@ extern	int	file_from_pak;	// global indicating that file came from a pak
 void COM_WriteFile (const char *filename, const void *data, int len);
 int COM_OpenFile (const char *filename, int *handle, unsigned int *path_id);
 int COM_FOpenFile (const char *filename, FILE **file, unsigned int *path_id);
+int COM_FileExists (const char *filename, unsigned int *path_id);
 void COM_CloseFile (int h);
 
 // these procedures open a file using COM_FindFile and loads it into a proper