Restore signal handlers when catching signals in edit_alloc()

edit_catcher() performs a longjmp via rc_raise() to the matching setjmp in
doit(). The latter does the same as before, so that edit_alloc() gets called
again, but this time the installation of the signal handlers trashes the old
handlers saved in the last call. Once readline() returns normally to
edit_alloc() the wrong signal handlers get restored.

The simplified call hierarchy looks like this:

doit();
  sigsetjmp();
    edit_alloc();
      oldint = sys_signal(SIGINT, edit_catcher);
      readline();
        SIGINT -> edit_catcher();
          siglongjmp();
      sys_signal(SIGINT, oldint);

Restoring the old signal handlers in edit_catcher() solves this.

4 files changed, 16 insertions, 4 deletions

diff --git a/edit-edit.c b/edit-edit.c
index c2a5260..7b2a9ab 100644
--- a/edit-edit.c
+++ b/edit-edit.c
@@ -37,7 +37,11 @@ void *edit_begin(int fd) {
 }
 
 
+static void (*oldint)(int), (*oldquit)(int);
+
 static void edit_catcher(int sig) {
+	sys_signal(SIGINT, oldint);
+	sys_signal(SIGQUIT, oldquit);
 	write(2, "\n", 1);
 	rc_raise(eError);
 }
@@ -46,7 +50,6 @@ char *edit_alloc(void *cookie, size_t *count) {
 	const char *r;
 	HistEvent he;
 	struct cookie *c = cookie;
-	void (*oldint)(int), (*oldquit)(int);
 
 	oldint = sys_signal(SIGINT, edit_catcher);
 	oldquit = sys_signal(SIGQUIT, edit_catcher);
diff --git a/edit-editline.c b/edit-editline.c
index 85e3f40..2069aef 100644
--- a/edit-editline.c
+++ b/edit-editline.c
@@ -29,7 +29,11 @@ void *edit_begin(int fd) {
 }
 
 /*
+static void (*oldint)(int), (*oldquit)(int);
+
 static void edit_catcher(int sig) {
+	sys_signal(SIGINT, oldint);
+	sys_signal(SIGQUIT, oldquit);
 	write(2, "\n", 1);
 	rc_raise(eError);
 }
@@ -42,7 +46,6 @@ char *edit_alloc(void *cookie, size_t *count) {
 	const char *r;
 	HistEvent he;
 	struct cookie *c = cookie;
-	void (*oldint)(int), (*oldquit)(int);
 
 	oldint = sys_signal(SIGINT, edit_catcher);
 	oldquit = sys_signal(SIGQUIT, edit_catcher);
diff --git a/edit-readline.c b/edit-readline.c
index 6a997c5..6d99d94 100644
--- a/edit-readline.c
+++ b/edit-readline.c
@@ -32,7 +32,11 @@ void *edit_begin(int fd) {
 	return c;
 }
 
+static void (*oldint)(int), (*oldquit)(int);
+
 static void edit_catcher(int sig) {
+	sys_signal(SIGINT, oldint);
+	sys_signal(SIGQUIT, oldquit);
 	write(2, "\n", 1);
 	rc_raise(eError);
 }
@@ -41,7 +45,6 @@ static char *prompt;
 
 char *edit_alloc(void *cookie, size_t *count) {
 	struct cookie *c = cookie;
-	void (*oldint)(int), (*oldquit)(int);
 
 	oldint = sys_signal(SIGINT, edit_catcher);
 	oldquit = sys_signal(SIGQUIT, edit_catcher);
diff --git a/edit-vrl.c b/edit-vrl.c
index 5c8ab5a..03c7e9e 100644
--- a/edit-vrl.c
+++ b/edit-vrl.c
@@ -32,7 +32,11 @@ void *edit_begin(int fd) {
 }
 
 /*
+static void (*oldint)(int), (*oldquit)(int);
+
 static void edit_catcher(int sig) {
+	sys_signal(SIGINT, oldint);
+	sys_signal(SIGQUIT, oldquit);
 	write(2, "\n", 1);
 	rc_raise(eError);
 }
@@ -45,7 +49,6 @@ char *edit_alloc(void *cookie, size_t *count) {
 	const char *r;
 	HistEvent he;
 	struct cookie *c = cookie;
-	void (*oldint)(int), (*oldquit)(int);
 
 	oldint = sys_signal(SIGINT, edit_catcher);
 	oldquit = sys_signal(SIGQUIT, edit_catcher);