From 51b2da657aa42b214a9aedeef60670b5037bb387 Mon Sep 17 00:00:00 2001
From: Jeff Squyres <jsquyres@cisco.com>
Date: Fri, 15 Oct 2004 11:42:54 +0000
Subject: [PATCH] Fix a problem where internal flex buffers were not getting
 properly reset when scanning a second file.

This commit was SVN r3158.
---
 src/mca/base/mca_base_parse_paramfile.c     |  1 +
 src/mca/base/mca_base_parse_paramfile_lex.h |  3 ++-
 src/mca/base/mca_base_parse_paramfile_lex.l | 19 +++++++++++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/mca/base/mca_base_parse_paramfile.c b/src/mca/base/mca_base_parse_paramfile.c
index 904f6e4fd2..5b8c0c6799 100644
--- a/src/mca/base/mca_base_parse_paramfile.c
+++ b/src/mca/base/mca_base_parse_paramfile.c
@@ -31,6 +31,7 @@ int mca_base_parse_paramfile(const char *paramfile)
     }
 
     mca_base_parse_done = false;
+    mca_base_param_init_buffer(mca_base_yyin);
     while (!mca_base_parse_done) {
         val = mca_base_yylex();
         switch (val) {
diff --git a/src/mca/base/mca_base_parse_paramfile_lex.h b/src/mca/base/mca_base_parse_paramfile_lex.h
index 36a3d2bf79..36f44a71a7 100644
--- a/src/mca/base/mca_base_parse_paramfile_lex.h
+++ b/src/mca/base/mca_base_parse_paramfile_lex.h
@@ -20,7 +20,8 @@
 
 #include <stdio.h>
 
-extern int mca_base_yylex(void);
+int mca_base_yylex(void);
+int mca_base_param_init_buffer(FILE *file);
 
 extern FILE *mca_base_yyin;
 extern bool mca_base_parse_done;
diff --git a/src/mca/base/mca_base_parse_paramfile_lex.l b/src/mca/base/mca_base_parse_paramfile_lex.l
index 319dfd548c..a024578ab1 100644
--- a/src/mca/base/mca_base_parse_paramfile_lex.l
+++ b/src/mca/base/mca_base_parse_paramfile_lex.l
@@ -62,8 +62,27 @@ static int finish_parsing(void)
     return YY_NULL;
 }
 
+
 static int mca_base_yywrap(void)
 {
     mca_base_parse_done = true;
     return 1;
 }
+
+
+/*
+ * Ensure that we have a valid yybuffer to use.  Specifically, if this
+ * scanner is invoked a second time, finish_parsing() (above) will
+ * have been executed, and the current buffer will have been freed.
+ * Flex doesn't recognize this fact because as far as it's concerned,
+ * its internal state was already initialized, so it thinks it should
+ * have a valid buffer.  Hence, here we ensure to give it a valid
+ * buffer.
+ */
+int mca_base_param_init_buffer(FILE *file)
+{
+    YY_BUFFER_STATE buf = yy_create_buffer(file, YY_BUF_SIZE);
+    yy_switch_to_buffer(buf);
+
+    return 0;
+}