With the improved escape sequence parser, it becomes easy to also improve

diagnostics.  Distinguish "incomplete escape sequence", "invalid special
character", and "unknown special character" from the generic "invalid
escape sequence", also promoting them from WARNING to ERROR because
incomplete escape sequences are severe syntax violations and because
encountering an invalid or unknown special character makes it likely
that part of the document content intended by the authors gets lost.

12 files changed, 70 insertions, 70 deletions

diff --git a/regress/char/accent/nocombine.out_lint b/regress/char/accent/nocombine.out_lint
index c9de4162..0f7be4d0 100644
--- a/regress/char/accent/nocombine.out_lint
+++ b/regress/char/accent/nocombine.out_lint
@@ -1,2 +1,2 @@
-mandoc: nocombine.in:8:27: WARNING: invalid escape sequence: \[']
-mandoc: nocombine.in:14:27: WARNING: invalid escape sequence: \[`]
+mandoc: nocombine.in:8:27: ERROR: invalid special character: \[']
+mandoc: nocombine.in:14:27: ERROR: invalid special character: \[`]
diff --git a/regress/char/space/invalid.out_lint b/regress/char/space/invalid.out_lint
index c05ef38f..4c146853 100644
--- a/regress/char/space/invalid.out_lint
+++ b/regress/char/space/invalid.out_lint
@@ -1,9 +1,9 @@
 mandoc: invalid.in:7:15: WARNING: invalid escape sequence: \[ 
-mandoc: invalid.in:8:14: WARNING: invalid escape sequence: \[%]
-mandoc: invalid.in:9:16: WARNING: invalid escape sequence: \[&]
-mandoc: invalid.in:10:12: WARNING: invalid escape sequence: \[:]
-mandoc: invalid.in:11:12: WARNING: invalid escape sequence: \[^]
-mandoc: invalid.in:12:16: WARNING: invalid escape sequence: \[_]
-mandoc: invalid.in:13:11: WARNING: invalid escape sequence: \[|]
-mandoc: invalid.in:14:12: WARNING: invalid escape sequence: \[~]
-mandoc: invalid.in:15:18: WARNING: invalid escape sequence: \[0]
+mandoc: invalid.in:8:14: ERROR: invalid special character: \[%]
+mandoc: invalid.in:9:16: ERROR: invalid special character: \[&]
+mandoc: invalid.in:10:12: ERROR: invalid special character: \[:]
+mandoc: invalid.in:11:12: ERROR: invalid special character: \[^]
+mandoc: invalid.in:12:16: ERROR: invalid special character: \[_]
+mandoc: invalid.in:13:11: ERROR: invalid special character: \[|]
+mandoc: invalid.in:14:12: ERROR: invalid special character: \[~]
+mandoc: invalid.in:15:18: ERROR: invalid special character: \[0]
diff --git a/regress/char/unicode/input.out_lint b/regress/char/unicode/input.out_lint
index 578a7704..fa36f876 100644
--- a/regress/char/unicode/input.out_lint
+++ b/regress/char/unicode/input.out_lint
@@ -24,11 +24,11 @@ mandoc: input.in:35:19: ERROR: skipping bad character: 0xbf
 mandoc: input.in:42:25: ERROR: skipping bad character: 0xed
 mandoc: input.in:42:26: ERROR: skipping bad character: 0xa0
 mandoc: input.in:42:27: ERROR: skipping bad character: 0x80
-mandoc: input.in:42:17: WARNING: invalid escape sequence: \[uD800]
+mandoc: input.in:42:17: ERROR: invalid special character: \[uD800]
 mandoc: input.in:43:25: ERROR: skipping bad character: 0xed
 mandoc: input.in:43:26: ERROR: skipping bad character: 0xbf
 mandoc: input.in:43:27: ERROR: skipping bad character: 0xbf
-mandoc: input.in:43:17: WARNING: invalid escape sequence: \[uDFFF]
+mandoc: input.in:43:17: ERROR: invalid special character: \[uDFFF]
 mandoc: input.in:53:19: ERROR: skipping bad character: 0xf0
 mandoc: input.in:53:20: ERROR: skipping bad character: 0x80
 mandoc: input.in:53:21: ERROR: skipping bad character: 0x80
@@ -57,25 +57,25 @@ mandoc: input.in:67:31: ERROR: skipping bad character: 0xf4
 mandoc: input.in:67:32: ERROR: skipping bad character: 0x90
 mandoc: input.in:67:33: ERROR: skipping bad character: 0x80
 mandoc: input.in:67:34: ERROR: skipping bad character: 0x80
-mandoc: input.in:67:21: WARNING: invalid escape sequence: \[u110000]
+mandoc: input.in:67:21: ERROR: invalid special character: \[u110000]
 mandoc: input.in:68:31: ERROR: skipping bad character: 0xf4
 mandoc: input.in:68:32: ERROR: skipping bad character: 0xbf
 mandoc: input.in:68:33: ERROR: skipping bad character: 0xbf
 mandoc: input.in:68:34: ERROR: skipping bad character: 0xbf
-mandoc: input.in:68:21: WARNING: invalid escape sequence: \[u13FFFF]
+mandoc: input.in:68:21: ERROR: invalid special character: \[u13FFFF]
 mandoc: input.in:69:31: ERROR: skipping bad character: 0xf5
 mandoc: input.in:69:32: ERROR: skipping bad character: 0x80
 mandoc: input.in:69:33: ERROR: skipping bad character: 0x80
 mandoc: input.in:69:34: ERROR: skipping bad character: 0x80
-mandoc: input.in:69:21: WARNING: invalid escape sequence: \[u140000]
+mandoc: input.in:69:21: ERROR: invalid special character: \[u140000]
 mandoc: input.in:70:31: ERROR: skipping bad character: 0xf7
 mandoc: input.in:70:32: ERROR: skipping bad character: 0xbf
 mandoc: input.in:70:33: ERROR: skipping bad character: 0xbf
 mandoc: input.in:70:34: ERROR: skipping bad character: 0xbf
-mandoc: input.in:70:21: WARNING: invalid escape sequence: \[u1FFFFF]
+mandoc: input.in:70:21: ERROR: invalid special character: \[u1FFFFF]
 mandoc: input.in:71:33: ERROR: skipping bad character: 0xf8
 mandoc: input.in:71:34: ERROR: skipping bad character: 0x88
 mandoc: input.in:71:35: ERROR: skipping bad character: 0x80
 mandoc: input.in:71:36: ERROR: skipping bad character: 0x80
 mandoc: input.in:71:37: ERROR: skipping bad character: 0x80
-mandoc: input.in:71:23: WARNING: invalid escape sequence: \[u200000]
+mandoc: input.in:71:23: ERROR: invalid special character: \[u200000]
diff --git a/regress/char/unicode/invalid.out_lint b/regress/char/unicode/invalid.out_lint
index ce9de988..0717605f 100644
--- a/regress/char/unicode/invalid.out_lint
+++ b/regress/char/unicode/invalid.out_lint
@@ -1,9 +1,9 @@
-mandoc: invalid.in:11:13: WARNING: invalid escape sequence: \[u2B]
-mandoc: invalid.in:11:20: WARNING: invalid escape sequence: \[u02B]
-mandoc: invalid.in:13:12: WARNING: invalid escape sequence: \[u0002B]
-mandoc: invalid.in:13:22: WARNING: invalid escape sequence: \[u00002B]
-mandoc: invalid.in:13:33: WARNING: invalid escape sequence: \[u000002B]
-mandoc: invalid.in:14:13: WARNING: invalid escape sequence: \[u110000]
-mandoc: invalid.in:14:24: WARNING: invalid escape sequence: \[u200000]
-mandoc: invalid.in:14:35: WARNING: invalid escape sequence: \[u1000000]
-mandoc: invalid.in:15:20: WARNING: invalid escape sequence: \[u1234g]
+mandoc: invalid.in:11:13: ERROR: unknown special character: \[u2B]
+mandoc: invalid.in:11:20: ERROR: unknown special character: \[u02B]
+mandoc: invalid.in:13:12: ERROR: invalid special character: \[u0002B]
+mandoc: invalid.in:13:22: ERROR: invalid special character: \[u00002B]
+mandoc: invalid.in:13:33: ERROR: unknown special character: \[u000002B]
+mandoc: invalid.in:14:13: ERROR: invalid special character: \[u110000]
+mandoc: invalid.in:14:24: ERROR: invalid special character: \[u200000]
+mandoc: invalid.in:14:35: ERROR: unknown special character: \[u1000000]
+mandoc: invalid.in:15:20: ERROR: unknown special character: \[u1234g]
diff --git a/regress/roff/char/badarg.out_lint b/regress/roff/char/badarg.out_lint
index e07faa3c..dd5c7999 100644
--- a/regress/roff/char/badarg.out_lint
+++ b/regress/roff/char/badarg.out_lint
@@ -1,6 +1,6 @@
 mandoc: badarg.in:6:6: ERROR: argument is not a character: char 
 mandoc: badarg.in:7:7: ERROR: argument is not a character: char \fR myval
-mandoc: badarg.in:8:7: WARNING: invalid escape sequence: \[myc]
+mandoc: badarg.in:8:7: ERROR: unknown special character: \[myc]
 mandoc: badarg.in:8:7: ERROR: argument is not a character: char \[myc]x myval
 mandoc: badarg.in:9:7: ERROR: argument is not a character: char xy myval
-mandoc: badarg.in:10:7: WARNING: invalid escape sequence: \[myc]
+mandoc: badarg.in:10:7: ERROR: unknown special character: \[myc]
diff --git a/regress/roff/esc/B.out_lint b/regress/roff/esc/B.out_lint
index f52270a4..fbaded65 100644
--- a/regress/roff/esc/B.out_lint
+++ b/regress/roff/esc/B.out_lint
@@ -1 +1 @@
-mandoc: B.in:37:23: WARNING: invalid escape sequence: \B'1+1
+mandoc: B.in:37:23: ERROR: incomplete escape sequence: \B'1+1
diff --git a/regress/roff/esc/ignore.out_lint b/regress/roff/esc/ignore.out_lint
index 16d64a97..ddbc8d6e 100644
--- a/regress/roff/esc/ignore.out_lint
+++ b/regress/roff/esc/ignore.out_lint
@@ -1,14 +1,14 @@
-mandoc: ignore.in:7:36: WARNING: invalid escape sequence: \[%]
-mandoc: ignore.in:8:35: WARNING: invalid escape sequence: \[&]
-mandoc: ignore.in:9:51: WARNING: invalid escape sequence: \[)]
-mandoc: ignore.in:10:37: WARNING: invalid escape sequence: \[,]
-mandoc: ignore.in:11:38: WARNING: invalid escape sequence: \[/]
-mandoc: ignore.in:12:28: WARNING: invalid escape sequence: \[^]
-mandoc: ignore.in:13:17: WARNING: invalid escape sequence: \[a]
-mandoc: ignore.in:14:25: WARNING: invalid escape sequence: \[d]
-mandoc: ignore.in:15:25: WARNING: invalid escape sequence: \[t]
-mandoc: ignore.in:16:33: WARNING: invalid escape sequence: \[u]
-mandoc: ignore.in:17:20: WARNING: invalid escape sequence: \[{]
-mandoc: ignore.in:18:25: WARNING: invalid escape sequence: \[|]
-mandoc: ignore.in:19:20: WARNING: invalid escape sequence: \[}]
-mandoc: ignore.in:23:56: WARNING: invalid escape sequence: \s-
+mandoc: ignore.in:7:36: ERROR: invalid special character: \[%]
+mandoc: ignore.in:8:35: ERROR: invalid special character: \[&]
+mandoc: ignore.in:9:51: ERROR: invalid special character: \[)]
+mandoc: ignore.in:10:37: ERROR: invalid special character: \[,]
+mandoc: ignore.in:11:38: ERROR: invalid special character: \[/]
+mandoc: ignore.in:12:28: ERROR: invalid special character: \[^]
+mandoc: ignore.in:13:17: ERROR: invalid special character: \[a]
+mandoc: ignore.in:14:25: ERROR: invalid special character: \[d]
+mandoc: ignore.in:15:25: ERROR: invalid special character: \[t]
+mandoc: ignore.in:16:33: ERROR: invalid special character: \[u]
+mandoc: ignore.in:17:20: ERROR: invalid special character: \[{]
+mandoc: ignore.in:18:25: ERROR: invalid special character: \[|]
+mandoc: ignore.in:19:20: ERROR: invalid special character: \[}]
+mandoc: ignore.in:23:56: ERROR: incomplete escape sequence: \s-
diff --git a/regress/roff/esc/invalid.out_lint b/regress/roff/esc/invalid.out_lint
index baef3176..ff52893f 100644
--- a/regress/roff/esc/invalid.out_lint
+++ b/regress/roff/esc/invalid.out_lint
@@ -1,43 +1,43 @@
 mandoc: invalid.in:7:8: WARNING: undefined escape, printing literally: \+
-mandoc: invalid.in:7:11: WARNING: invalid escape sequence: \[+]
+mandoc: invalid.in:7:11: ERROR: invalid special character: \[+]
 mandoc: invalid.in:8:13: WARNING: undefined escape, printing literally: \;
-mandoc: invalid.in:8:16: WARNING: invalid escape sequence: \[;]
+mandoc: invalid.in:8:16: ERROR: invalid special character: \[;]
 mandoc: invalid.in:9:13: WARNING: undefined escape, printing literally: \<
-mandoc: invalid.in:9:16: WARNING: invalid escape sequence: \[<]
+mandoc: invalid.in:9:16: ERROR: invalid special character: \[<]
 mandoc: invalid.in:10:12: WARNING: undefined escape, printing literally: \=
-mandoc: invalid.in:10:15: WARNING: invalid escape sequence: \[=]
+mandoc: invalid.in:10:15: ERROR: invalid special character: \[=]
 mandoc: invalid.in:11:16: WARNING: undefined escape, printing literally: \>
-mandoc: invalid.in:11:19: WARNING: invalid escape sequence: \[>]
+mandoc: invalid.in:11:19: ERROR: invalid special character: \[>]
 mandoc: invalid.in:12:6: WARNING: undefined escape, printing literally: \@
-mandoc: invalid.in:12:9: WARNING: invalid escape sequence: \[@]
+mandoc: invalid.in:12:9: ERROR: invalid special character: \[@]
 mandoc: invalid.in:13:18: WARNING: undefined escape, printing literally: \]
-mandoc: invalid.in:14:16: WARNING: invalid escape sequence: \[{]
-mandoc: invalid.in:14:21: WARNING: invalid escape sequence: \[}]
+mandoc: invalid.in:14:16: ERROR: invalid special character: \[{]
+mandoc: invalid.in:14:21: ERROR: invalid special character: \[}]
 mandoc: invalid.in:15:9: WARNING: undefined escape, printing literally: \1
-mandoc: invalid.in:15:12: WARNING: invalid escape sequence: \[1]
+mandoc: invalid.in:15:12: ERROR: invalid special character: \[1]
 mandoc: invalid.in:16:5: WARNING: undefined escape, printing literally: \G
-mandoc: invalid.in:16:8: WARNING: invalid escape sequence: \[G]
+mandoc: invalid.in:16:8: ERROR: invalid special character: \[G]
 mandoc: invalid.in:17:5: WARNING: undefined escape, printing literally: \I
-mandoc: invalid.in:17:8: WARNING: invalid escape sequence: \[I]
+mandoc: invalid.in:17:8: ERROR: invalid special character: \[I]
 mandoc: invalid.in:18:5: WARNING: undefined escape, printing literally: \i
-mandoc: invalid.in:18:8: WARNING: invalid escape sequence: \[i]
+mandoc: invalid.in:18:8: ERROR: invalid special character: \[i]
 mandoc: invalid.in:19:5: WARNING: undefined escape, printing literally: \J
-mandoc: invalid.in:19:8: WARNING: invalid escape sequence: \[J]
+mandoc: invalid.in:19:8: ERROR: invalid special character: \[J]
 mandoc: invalid.in:20:5: WARNING: undefined escape, printing literally: \j
-mandoc: invalid.in:20:8: WARNING: invalid escape sequence: \[j]
+mandoc: invalid.in:20:8: ERROR: invalid special character: \[j]
 mandoc: invalid.in:21:5: WARNING: undefined escape, printing literally: \K
-mandoc: invalid.in:21:8: WARNING: invalid escape sequence: \[K]
+mandoc: invalid.in:21:8: ERROR: invalid special character: \[K]
 mandoc: invalid.in:22:5: WARNING: undefined escape, printing literally: \P
-mandoc: invalid.in:22:8: WARNING: invalid escape sequence: \[P]
+mandoc: invalid.in:22:8: ERROR: invalid special character: \[P]
 mandoc: invalid.in:23:5: WARNING: undefined escape, printing literally: \Q
-mandoc: invalid.in:23:8: WARNING: invalid escape sequence: \[Q]
+mandoc: invalid.in:23:8: ERROR: invalid special character: \[Q]
 mandoc: invalid.in:24:5: WARNING: undefined escape, printing literally: \q
-mandoc: invalid.in:24:8: WARNING: invalid escape sequence: \[q]
+mandoc: invalid.in:24:8: ERROR: invalid special character: \[q]
 mandoc: invalid.in:25:5: WARNING: undefined escape, printing literally: \T
-mandoc: invalid.in:25:8: WARNING: invalid escape sequence: \[T]
+mandoc: invalid.in:25:8: ERROR: invalid special character: \[T]
 mandoc: invalid.in:26:5: WARNING: undefined escape, printing literally: \U
-mandoc: invalid.in:26:8: WARNING: invalid escape sequence: \[U]
+mandoc: invalid.in:26:8: ERROR: invalid special character: \[U]
 mandoc: invalid.in:27:5: WARNING: undefined escape, printing literally: \W
-mandoc: invalid.in:27:8: WARNING: invalid escape sequence: \[W]
+mandoc: invalid.in:27:8: ERROR: invalid special character: \[W]
 mandoc: invalid.in:28:5: WARNING: undefined escape, printing literally: \y
-mandoc: invalid.in:28:8: WARNING: invalid escape sequence: \[y]
+mandoc: invalid.in:28:8: ERROR: invalid special character: \[y]
diff --git a/regress/roff/esc/unsupp.out_lint b/regress/roff/esc/unsupp.out_lint
index fae97c81..db7631c6 100644
--- a/regress/roff/esc/unsupp.out_lint
+++ b/regress/roff/esc/unsupp.out_lint
@@ -1,5 +1,5 @@
 mandoc: unsupp.in:7:20: UNSUPP: unsupported escape sequence: \!
-mandoc: unsupp.in:7:23: WARNING: invalid escape sequence: \[!]
+mandoc: unsupp.in:7:23: ERROR: invalid special character: \[!]
 mandoc: unsupp.in:8:17: UNSUPP: unsupported escape sequence: \?
 mandoc: unsupp.in:8:21: UNSUPP: unsupported escape sequence: \?
-mandoc: unsupp.in:8:24: WARNING: invalid escape sequence: \[?]
+mandoc: unsupp.in:8:24: ERROR: invalid special character: \[?]
diff --git a/regress/roff/esc/w.out_lint b/regress/roff/esc/w.out_lint
index d48495c2..11dfbef5 100644
--- a/regress/roff/esc/w.out_lint
+++ b/regress/roff/esc/w.out_lint
@@ -1 +1 @@
-mandoc: w.in:17:15: WARNING: invalid escape sequence: \w'foo
+mandoc: w.in:17:15: ERROR: incomplete escape sequence: \w'foo
diff --git a/regress/roff/nr/escname.out_lint b/regress/roff/nr/escname.out_lint
index edec17fa..8655da96 100644
--- a/regress/roff/nr/escname.out_lint
+++ b/regress/roff/nr/escname.out_lint
@@ -1,5 +1,5 @@
 mandoc: escname.in:9:5: ERROR: escaped character not allowed in a name: first\e
 mandoc: escname.in:11:10: WARNING: undefined escape, printing literally: \G
 mandoc: escname.in:14:5: ERROR: escaped character not allowed in a name: first\e
-mandoc: escname.in:20:13: WARNING: invalid escape sequence: \n[second
+mandoc: escname.in:20:13: ERROR: incomplete escape sequence: \n[second
 mandoc: escname.in:20:12: STYLE: whitespace at end of input line
diff --git a/regress/roff/string/name.out_lint b/regress/roff/string/name.out_lint
index 13283f5d..55f1f87b 100644
--- a/regress/roff/string/name.out_lint
+++ b/regress/roff/string/name.out_lint
@@ -1,6 +1,6 @@
 mandoc: name.in:11:5: ERROR: escaped character not allowed in a name: bs\e
 mandoc: name.in:14:5: ERROR: escaped character not allowed in a name: bl\ 
-mandoc: name.in:18:29: WARNING: invalid escape sequence: \*[norm
+mandoc: name.in:18:29: ERROR: incomplete escape sequence: \*[norm
 mandoc: name.in:18:28: STYLE: whitespace at end of input line
 mandoc: name.in:20:7: WARNING: undefined string, using "": quot
 mandoc: name.in:20:6: STYLE: whitespace at end of input line