sam: attempt to make x/y commands more robust

These commands can be followed by an address which changes the
range to which the sub command applies. The looping construct
should then continue at the position of the last change within
the original range.

A previously problemeatic example:

 :sam x/^static/ .,+/^\}/ c/replaced

1 files changed, 8 insertions, 4 deletions

diff --git a/sam.c b/sam.c
index 69f57da..8956c47 100644
--- a/sam.c
+++ b/sam.c
@@ -685,14 +685,15 @@ static Filerange address_evaluate(Address *addr, File *file, Filerange *range, i
 
 static bool sam_execute(Vis *vis, Win *win, Command *cmd, Filerange *range) {
 	bool ret = true;
-	Filerange r = cmd->address ? address_evaluate(cmd->address, win->file, range, 0) : *range;
+	if (cmd->address)
+		*range = address_evaluate(cmd->address, win->file, range, 0);
 
 	switch (cmd->argv[0][0]) {
 	case '{':
 	{
 		Text *txt = win->file->text;
 		Mark start, end;
-		Filerange group = r;
+		Filerange group = *range;
 
 		for (Command *c = cmd->cmd; c; c = c->next) {
 			if (!text_range_valid(&group))
@@ -712,7 +713,7 @@ static bool sam_execute(Vis *vis, Win *win, Command *cmd, Filerange *range) {
 		break;
 	}
 	default:
-		ret = cmd->cmddef->func(vis, win, cmd, &r);
+		ret = cmd->cmddef->func(vis, win, cmd, range);
 		break;
 	}
 	return ret;
@@ -823,6 +824,8 @@ static bool cmd_extract(Vis *vis, Win *win, Command *cmd, Filerange *range) {
 				Mark mark_end = text_mark_set(txt, end);
 				ret &= sam_execute(vis, win, cmd->cmd, &r);
 				last_start = start = text_mark_get(txt, mark_start);
+				if (start == EPOS && last_start != r.end)
+					last_start = start = r.end;
 				end = text_mark_get(txt, mark_end);
 				if (start == EPOS || end == EPOS)
 					return false;
@@ -870,7 +873,8 @@ static bool cmd_select(Vis *vis, Win *win, Command *cmd, Filerange *range) {
 			cursor = view_cursors_new(view, text_size(txt)+1);
 			view_cursors_dispose(c);
 		}
-		ret &= sam_execute(vis, win, cmd->cmd, &sel);
+		if (text_range_valid(&sel))
+			ret &= sam_execute(vis, win, cmd->cmd, &sel);
 	}
 
 	if (cursor && !view_cursors_dispose(cursor)) {