util: introduce util.debugstacktrace for showing a stack trace without crashing
This is often very handy when hacking/debugging.
Calling util.debugstacktrace('hey') from a place in hg will give something like:
hey at:
./hg:38 in <module>
/home/user/hgsrc/mercurial/dispatch.py:28 in run
/home/user/hgsrc/mercurial/dispatch.py:65 in dispatch
/home/user/hgsrc/mercurial/dispatch.py:88 in _runcatch
/home/user/hgsrc/mercurial/dispatch.py:740 in _dispatch
/home/user/hgsrc/mercurial/dispatch.py:514 in runcommand
/home/user/hgsrc/mercurial/dispatch.py:830 in _runcommand
/home/user/hgsrc/mercurial/dispatch.py:801 in checkargs
/home/user/hgsrc/mercurial/dispatch.py:737 in <lambda>
/home/user/hgsrc/mercurial/util.py:472 in check
...
$ hg init a
$ cd a
$ hg diff inexistent1 inexistent2
inexistent1: * (glob)
inexistent2: * (glob)
$ echo bar > foo
$ hg add foo
$ hg ci -m 'add foo'
$ echo foobar > foo
$ hg ci -m 'change foo'
$ hg --quiet diff -r 0 -r 1
--- a/foo Thu Jan 01 00:00:00 1970 +0000
+++ b/foo Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +1,1 @@
-bar
+foobar
$ hg diff -r 0 -r 1
diff -r a99fb63adac3 -r 9b8568d3af2f foo
--- a/foo Thu Jan 01 00:00:00 1970 +0000
+++ b/foo Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +1,1 @@
-bar
+foobar
$ hg --verbose diff -r 0 -r 1
diff -r a99fb63adac3 -r 9b8568d3af2f foo
--- a/foo Thu Jan 01 00:00:00 1970 +0000
+++ b/foo Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +1,1 @@
-bar
+foobar
$ hg --debug diff -r 0 -r 1
diff -r a99fb63adac3f31816a22f665bc3b7a7655b30f4 -r 9b8568d3af2f1749445eef03aede868a6f39f210 foo
--- a/foo Thu Jan 01 00:00:00 1970 +0000
+++ b/foo Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +1,1 @@
-bar
+foobar
$ cd ..