Flush the logfile reasonably frequently in `printable output only' and

`all session data' modes, without completely mauling the performance, by
fflush()ing once per term_out(). If anyone complains I suppose we can
make this optional.

[originally from svn r4445]

logging.c

@@ -34,6 +34,16 @@ void logtraffic(void *handle, unsigned char c, int logmode)
     }
 }
 
+/*
+ * Flush any open log file.
+ */
+void logflush(void *handle) {
+    struct LogContext *ctx = (struct LogContext *)handle;
+    if (ctx->cfg.logtype > 0)
+	if (ctx->lgfp)
+	    fflush(ctx->lgfp);
+}
+
 /*
  * Log an Event Log entry. Used in SSH packet logging mode; this is
  * also as convenient a place as any to put the output of Event Log

putty.h

@@ -655,6 +655,7 @@ void log_reconfig(void *logctx, Config *cfg);
 void logfopen(void *logctx);
 void logfclose(void *logctx);
 void logtraffic(void *logctx, unsigned char c, int logmode);
+void logflush(void *logctx);
 void log_eventlog(void *logctx, const char *string);
 enum { PKT_INCOMING, PKT_OUTGOING };
 void log_packet(void *logctx, int direction, int type,

terminal.c

@@ -3311,6 +3311,7 @@ void term_out(Terminal *term)
     }
 
     term_print_flush(term);
+    logflush(term->logctx);
 }
 
 #if 0