[LyX/master] Refactor file-name sanitisation.

[Thibaut Cuvelier]

commit 0b5e94072313045b1adf53dd88d45a78e460bfbe
Author: Thibaut Cuvelier <tcuvelier at lyx.org>
Date:   Tue Oct 19 02:30:47 2021 +0200

    Refactor file-name sanitisation.
    
    For now, this is only used in FileName, because it does not change the semantics of DocFileName::mangledFileName.
---
 src/support/FileName.cpp  |   13 +------------
 src/support/filetools.cpp |   21 +++++++++++++++++++++
 src/support/filetools.h   |    4 ++++
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/src/support/FileName.cpp b/src/support/FileName.cpp
index 5d70dd2..8ad7e00 100644
--- a/src/support/FileName.cpp
+++ b/src/support/FileName.cpp
@@ -977,18 +977,7 @@ string DocFileName::mangledFileName(string const & dir, bool use_counter, bool e
 		mname = "export_" + onlyFileName() + "_" + toHexHash(mname);
 
 	// The mangled name must be a valid LaTeX name.
-	// The list of characters to keep is probably over-restrictive,
-	// but it is not really a problem.
-	// Apart from non-ASCII characters, at least the following characters
-	// are forbidden: '/', '.', ' ', and ':'.
-	// On windows it is not possible to create files with '<', '>' or '?'
-	// in the name.
-	static string const keep = "abcdefghijklmnopqrstuvwxyz"
-				   "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-				   "+-0123456789;=";
-	string::size_type pos = 0;
-	while ((pos = mname.find_first_not_of(keep, pos)) != string::npos)
-		mname[pos++] = '_';
+	mname = sanitizeFileName(mname);
 	// Add the extension back on
 	mname = support::changeExtension(mname, getExtension(name));
 
diff --git a/src/support/filetools.cpp b/src/support/filetools.cpp
index d022115..cfb245c 100644
--- a/src/support/filetools.cpp
+++ b/src/support/filetools.cpp
@@ -1325,5 +1325,26 @@ std::string toHexHash(const std::string & str)
 	return fromqstr(QString(hash.toHex()));
 }
 
+
+std::string sanitizeFileName(const std::string & str)
+{
+	// The list of characters to keep is probably over-restrictive,
+	// but it is not really a problem.
+	// Apart from non-ASCII characters, at least the following characters
+	// are forbidden: '/', '.', ' ', and ':'.
+	// On windows it is not possible to create files with '<', '>' or '?'
+	// in the name.
+	static std::string const keep = "abcdefghijklmnopqrstuvwxyz"
+	                           "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	                           "+-0123456789;=";
+
+	std::string name = str;
+	string::size_type pos = 0;
+	while ((pos = name.find_first_not_of(keep, pos)) != string::npos)
+		name[pos++] = '_';
+
+	return name;
+}
+
 } // namespace support
 } // namespace lyx
diff --git a/src/support/filetools.h b/src/support/filetools.h
index 84b2378..404dec2 100644
--- a/src/support/filetools.h
+++ b/src/support/filetools.h
@@ -354,6 +354,10 @@ void fileUnlock(int fd, const char * lock_file);
  */
 std::string toHexHash(const std::string & str);
 
+/// Replace non-ASCII characters to ensure that the string can be used as a
+/// file name on all platforms and as a LaTeX name.
+std::string sanitizeFileName(const std::string & str);
+
 } // namespace support
 } // namespace lyx