Improve \AA and \aa tex2lyx import

The lib/unicodesymbols part is based on work by Günter Milde:

Both, \r{A} and \AA (rsp. \r{a} and \aa) are equivalent standard LICR macros
for Aring/aring  as well as the deprecated "angstrom sign" character (212B).

However, with \AA for 212B and \r{A} for 00C5, tex2lyx converts \AA to the
deprecated "angstrom sign" which is missing in many fonts including the
Unicode version of Latin Modern.

I added the normalize_c() calls so that tex2lyx prefers the precomposed forms
(these are better editable in LyX) and the deprecated flag.

lib/unicodesymbols

@@ -48,6 +48,7 @@
 # - notermination=both Do not terminate this textcommand and mathcommand (by {} or space).
 # - notermination=none Always terminate this textcommand and mathcommand (by {} or space).
 # - tipashortcut=<shortcut> Shortcut notation for TIPA
+# - deprecated         Do not use this symbol for backwards conversion in LyX and tex2lyx.
 
 0x00a0 "~"                        "" "notermination=both" "~" "" # NO-BREAK SPACE
 0x00a1 "\\textexclamdown"         "" "" # INVERTED EXCLAMATION MARK
@@ -86,7 +87,7 @@
 0x00c2 "\\^{A}"                   "" "mathalpha" "\\hat{A}" # LATIN CAPITAL LETTER A WITH CIRCUMFLEX
 0x00c3 "\\~{A}"                   "" "mathalpha" "\\tilde{A}" # LATIN CAPITAL LETTER A WITH TILDE
 0x00c4 "\\\"{A}"                  "" "mathalpha" "\\ddot{A}" # LATIN CAPITAL LETTER A WITH DIAERESIS
-0x00c5 "\\r{A}"                   "" "mathalpha" "\\mathring{A}" # LATIN CAPITAL LETTER A WITH RING ABOVE
+0x00c5 "\\AA"                     "" "mathalpha" "\\mathring{A}" "" # LATIN CAPITAL LETTER A WITH RING ABOVE
 0x00c6 "\\AE"                     "" "" # LATIN CAPITAL LETTER AE
 0x00c7 "\\c{C}"                   "" "mathalpha" "\\cedilla{C}" "accents,cedilla" # LATIN CAPITAL LETTER C WITH CEDILLA
 0x00c8 "\\`{E}"                   "" "mathalpha" "\\grave{E}" # LATIN CAPITAL LETTER E WITH GRAVE
@@ -118,7 +119,7 @@
 0x00e2 "\\^{a}"                   "" "mathalpha" "\\hat{a}" # LATIN SMALL LETTER A WITH CIRCUMFLEX
 0x00e3 "\\~{a}"                   "" "mathalpha" "\\tilde{a}" # LATIN SMALL LETTER A WITH TILDE
 0x00e4 "\\\"{a}"                  "" "mathalpha" "\\ddot{a}" # LATIN SMALL LETTER A WITH DIAERESIS
-0x00e5 "\\r{a}"                   "" "mathalpha" "\\mathring{a}" # LATIN SMALL LETTER A WITH RING ABOVE
+0x00e5 "\\aa"                     "" "mathalpha" "\\mathring{a}" "" # LATIN SMALL LETTER A WITH RING ABOVE
 0x00e6 "\\ae"                     "" "" # LATIN SMALL LETTER AE
 0x00e7 "\\c{c}"                   "" "mathalpha" "\\cedilla{c}" "accents,cedilla" # LATIN SMALL LETTER C WITH CEDILLA
 0x00e8 "\\`{e}"                   "" "mathalpha" "\\grave{e}" # LATIN SMALL LETTER E WITH GRAVE
@@ -1882,7 +1883,7 @@
 0x2128 ""                         "" "" "\\mathfrak{Z}" "amssymb" # BLACK-LETTER CAPITAL Z
 #0x2129 ""                         "" "" "" "" # TURNED GREEK SMALL LETTER IOTA
 0x212a "K"                        "" "notermination=text" "" "" # KELVIN SIGN
-0x212b "\\AA"                     "" "force=utf8" "" "" # ANGSTROM SIGN
+0x212b "\\AA"                     "" "force=utf8,deprecated" "" "" # ANGSTROM SIGN
 0x212c ""                         "" "" "\\mathscr{B}" "mathrsfs" # SCRIPT CAPITAL B
 0x212d ""                         "" "" "\\mathfrak{C}" "amssymb" # BLACK-LETTER CAPITAL C
 0x212e "\\textestimated"          "textcomp" "" # ESTIMATED SYMBOL

src/Encoding.cpp

@@ -317,6 +317,8 @@ char_type Encodings::fromLaTeXCommand(docstring const & cmd, int cmdtype,
 	CharInfoMap::const_iterator const end = unicodesymbols.end();
 	CharInfoMap::const_iterator it = unicodesymbols.begin();
 	for (combining = false; it != end; ++it) {
+		if (it->second.deprecated())
+			continue;
 		docstring const math = it->second.mathcommand();
 		docstring const text = it->second.textcommand();
 		if ((cmdtype & MATH_CMD) && math == cmd) {
@@ -402,6 +404,8 @@ docstring Encodings::fromLaTeXCommand(docstring const & cmd, int cmdtype,
 		size_t unicmd_size = 0;
 		char_type c = 0;
 		for (; it != uniend; ++it) {
+			if (it->second.deprecated())
+				continue;
 			docstring const math = mathmode ? it->second.mathcommand()
 							: docstring();
 			docstring const text = textmode ? it->second.textcommand()
@@ -722,6 +726,8 @@ void Encodings::read(FileName const & encfile, FileName const & symbolsfile)
 				flags &= ~CharInfoMathNoTermination;
 			} else if (contains(flag, "tipashortcut=")) {
 				tipashortcut = split(flag, '=');
+			} else if (flag == "deprecated") {
+				flags |= CharInfoDeprecated;
 			} else {
 				lyxerr << "Ignoring unknown flag `" << flag
 				       << "' for symbol `0x"

src/Encoding.h

@@ -52,6 +52,8 @@ enum CharInfoFlags {
 	CharInfoMathNoTermination = 32,
 	///
 	CharInfoForceSelected = 64,
+	///
+	CharInfoDeprecated = 128
 };
 
 
@@ -86,6 +88,8 @@ public:
 	bool force() const { return flags_ & CharInfoForce ? true : false; }
 	/// Force the LaTeX command for some encodings?
 	bool forceselected() const { return flags_ & CharInfoForceSelected ? true : false; }
+	/// Disable LaTeX command => char_type conversion for this deprecated symbol?
+	bool deprecated() const { return flags_ & CharInfoDeprecated ? true : false; }
 	/// TIPA shortcut
 	std::string const tipashortcut() const { return tipashortcut_; }
 	/// \c textcommand needs no termination (such as {} or space).

src/tex2lyx/test/test-insets.lyx.lyx

@@ -6907,29 +6907,7 @@ Other symbols
 \end_layout
 
 \begin_layout Standard
-All three should be converted to U+00C5: Å Å Å (not U+212B). All three should be converted to U+00E5: 
+All three should be converted to U+00C5: Å Å Å (not U+212B). All three should be converted to U+00E5: å å å.
-\begin_inset ERT
-status collapsed
-
-\begin_layout Plain Layout
-
-\backslash
-aa
-\end_layout
-
-\end_inset
-
-
-\begin_inset ERT
-status collapsed
-
-\begin_layout Plain Layout
-{}
-\end_layout
-
-\end_inset
-
- å å.
 \end_layout
 
 \begin_layout Subsection

src/tex2lyx/text.cpp

@@ -521,8 +521,8 @@ docstring convert_unicodesymbols(docstring s)
 		bool termination;
 		docstring rem;
 		set<string> req;
-		docstring parsed = encodings.fromLaTeXCommand(s,
+		docstring parsed = normalize_c(encodings.fromLaTeXCommand(s,
-				Encodings::TEXT_CMD, termination, rem, &req);
+				Encodings::TEXT_CMD, termination, rem, &req));
 		set<string>::const_iterator it = req.begin();
 		set<string>::const_iterator en = req.end();
 		for (; it != en; ++it)
@@ -4824,8 +4824,8 @@ void parse_text(Parser & p, ostream & os, unsigned flags, bool outer,
 			bool termination;
 			docstring rem;
 			set<string> req;
-			docstring s = encodings.fromLaTeXCommand(from_utf8(name),
+			docstring s = normalize_c(encodings.fromLaTeXCommand(from_utf8(name),
-					Encodings::TEXT_CMD, termination, rem, &req);
+					Encodings::TEXT_CMD, termination, rem, &req));
 			if (!s.empty()) {
 				context.check_layout(os);
 				os << to_utf8(s);