Emacs: indent relative to enclosing block

This changes the indent to calculate positions relative to the enclosing
block (or braced/parenthesized expression), rather than by an absolute
nesting level within the whole file.  This allows things like this to
work:

    let x =
        match expr {
            Pattern => ...
        }

With the old method, only one level of nesting would be added within the
match braces, so "Pattern" would have ended up aligned with the match.

The other change is that multiple parens/braces on the same line only
increase the indent once.  This is a very common case for passing
closures/procs.  The absolute nesting method would do this:

    spawn(proc() {
            // Indented out two indent levels...
    })

whereas the code in this commit does this:

    spawn(proc() {
        // Indented out only one level...
    })

1 files changed, 64 insertions, 0 deletions

diff --git a/rust-mode-tests.el b/rust-mode-tests.el
index c0543b6..bdd7d63 100644
--- a/rust-mode-tests.el
+++ b/rust-mode-tests.el
@@ -452,6 +452,70 @@ fn foo() {
 "
    ))
 
+(ert-deftest indent-indented-match ()
+  (test-indent
+   "
+fn foo() {
+    let x = 
+        match blah {
+            Pattern |
+            Pattern2 => {
+                hello()
+            },
+            _ => whatever
+        };
+    y();
+}
+"
+   ))
+
+(ert-deftest indent-curly-braces-within-parens ()
+  (test-indent
+   "
+fn foo() {
+    let x = 
+        foo(bar(|x| {
+            only_one_indent_here();
+        }));
+    y();
+}
+"
+   ))
+
+(ert-deftest indent-weirdly-indented-block ()
+  (rust-test-manip-code
+   "
+fn foo() {
+ {
+this_block_is_over_to_the_left_for_some_reason();
+ }
+
+}
+"
+   16
+   #'indent-for-tab-command
+   "
+fn foo() {
+ {
+     this_block_is_over_to_the_left_for_some_reason();
+ }
+
+}
+"
+   ))
+
+(ert-deftest indent-multi-line-attrib ()
+  (test-indent
+   "
+#[attrib(
+    this,
+    that,
+    theotherthing)]
+mod function_with_multiline_attribute() {}
+"
+   ))
+
+
 ;; Make sure that in effort to cover match patterns we don't mistreat || or expressions
 (ert-deftest indent-nonmatch-or-expression ()
   (test-indent