First go at separating errors and keyboard interrupts

This is the first posting exactly as was, with known errors and
omissions.

Basic strategy is to introduce bits to errflag and to set and
reset them separately.

1 files changed, 17 insertions, 3 deletions

diff --git a/Src/Zle/zle_tricky.c b/Src/Zle/zle_tricky.c
index b15d91c8e..864f804b7 100644
--- a/Src/Zle/zle_tricky.c
+++ b/Src/Zle/zle_tricky.c
@@ -829,7 +829,7 @@ docomplete(int lst)
 	    if (olst == COMP_EXPAND_COMPLETE &&
 		!strcmp(ol, zlemetaline)) {
 		zlemetacs = ocs;
-		errflag = 0;
+		errflag &= ~ERRFLAG_ERROR;
 
 		if (!compfunc) {
 		    char *p;
@@ -877,6 +877,19 @@ docomplete(int lst)
 
     active = 0;
     makecommaspecial(0);
+
+    /*
+     * As a special case, we reset user interrupts here.
+     * That's because completion is an intensive piece of
+     * computation that the user might want to interrupt separately
+     * from anything else going on.  If they do, they probably
+     * want to keep the line edit buffer intact.
+     *
+     * There's a race here that the user might hit ^C just
+     * after completion exited anyway, but that's inevitable.
+     */
+    errflag &= ~ERRFLAG_INT;
+
     return dat[1];
 }
 
@@ -1394,7 +1407,8 @@ get_comp_string(void)
     }
     strinend();
     inpop();
-    errflag = lexflags = 0;
+    lexflags = 0;
+    errflag &= ~ERRFLAG_ERROR;
     if (parbegin != -1) {
 	/* We are in command or process substitution if we are not in
 	 * a $((...)). */
@@ -2917,7 +2931,7 @@ getcurcmd(void)
     popheap();
     strinend();
     inpop();
-    errflag = 0;
+    errflag &= ~ERRFLAG_ERROR;
     unmetafy_line();
     lexrestore();