eval: Restore input files in evalcommand

Commit Message

Herbert Xu March 26, 2018, 4:39 p.m. UTC

When evalcommand invokes a command that modifies parsefile and
then bails out without popping the file, we need to ensure the
input file is restored so that the shell can continue to execute.

Reported-by: Martijn Dekker <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

Patch

diff --git a/src/eval.c b/src/eval.c
index 7498f9d..e5749ef 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -694,6 +694,7 @@  evalcommand(union node *cmd, int flags)
 #endif
 {
 	struct localvar_list *localvar_stop;
+	struct parsefile *file_stop;
 	struct redirtab *redir_stop;
 	struct stackmark smark;
 	union node *argp;
@@ -722,6 +723,7 @@  evalcommand(union node *cmd, int flags)
 	TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
 	setstackmark(&smark);
 	localvar_stop = pushlocalvars();
+	file_stop = parsefile;
 	back_exitstatus = 0;
 
 	cmdentry.cmdtype = CMDBUILTIN;
@@ -895,6 +897,7 @@  out:
 	if (cmd->ncmd.redirect)
 		popredir(execcmd);
 	unwindredir(redir_stop);
+	unwindfiles(file_stop);
 	unwindlocalvars(localvar_stop);
 	if (lastarg)
 		/* dsl: I think this is intended to be used to support
diff --git a/src/input.c b/src/input.c
index e53423c..ae0c4c8 100644
--- a/src/input.c
+++ b/src/input.c
@@ -479,6 +479,13 @@  popfile(void)
 }
 
 
+void unwindfiles(struct parsefile *stop)
+{
+	while (parsefile != stop)
+		popfile();
+}
+
+
 /*
  * Return to top level.
  */
@@ -486,8 +493,7 @@  popfile(void)
 void
 popallfiles(void)
 {
-	while (parsefile != &basepf)
-		popfile();
+	unwindfiles(&basepf);
 }
 
 
diff --git a/src/input.h b/src/input.h
index ec97c1d..a9c0517 100644
--- a/src/input.h
+++ b/src/input.h
@@ -97,5 +97,6 @@  void popstring(void);
 int setinputfile(const char *, int);
 void setinputstring(char *);
 void popfile(void);
+void unwindfiles(struct parsefile *);
 void popallfiles(void);
 void closescript(void);