Fix bug #9146.

If LyX does not know about a given file format, it may easily
happen that the format is recognized as "latex" and this causes
bug #9146. This patch limits the check for a latex format to
non-binary files. The strategy for deciding that a file has
binary content is the same as that adopted by the "less" program.

diff --git a/src/Format.cpp b/src/Format.cpp
index e2d23b5c652f57c08493cd28f3856d6ceae64fbd..ff7fb3461366aee11199f6991093eb198435ee55 100644 (file)
--- a/src/Format.cpp
+++ b/src/Format.cpp
@@ -241,12 +241,17 @@ string guessFormatFromContents(FileName const & fn)
        int const max_count = 50;
        int count = 0;
 
+       // Maximum number of binary chars allowed for latex detection
+       int const max_bin = 5;
+
        string str;
        string format;
        bool firstLine = true;
        bool backslash = false;
+       bool maybelatex = false;
+       int binchars = 0;
        int dollars = 0;
-       while ((count++ < max_count) && format.empty()) {
+       while ((count++ < max_count) && format.empty() && binchars <= max_bin) {
                if (ifs.eof())
                        break;
 
@@ -364,16 +369,20 @@ string guessFormatFromContents(FileName const & fn)
                         contains(str, "$$") ||
                         contains(str, "\\[") ||
                         contains(str, "\\]"))
-                       format = "latex";
+                       maybelatex = true;
                else {
                        if (contains(str, '\\'))
                                backslash = true;
                        dollars += count_char(str, '$');
+                       if (backslash && dollars > 1)
+                               // inline equation
+                               maybelatex = true;
                }
+
+               binchars += count_bin_chars(str);
        }
 
-       if (format.empty() && backslash && dollars > 1)
-               // inline equation
+       if (format.empty() && binchars <= max_bin && maybelatex)
                format = "latex";
 
        if (format.empty()) {

diff --git a/src/support/lstrings.cpp b/src/support/lstrings.cpp
index a43feeba13f0625ac766c612bb11cf3f8ba3ec32..8508e4ef1303e06e7e34d3e560b387f7ee142194 100644 (file)
--- a/src/support/lstrings.cpp
+++ b/src/support/lstrings.cpp
@@ -943,6 +943,31 @@ int count_char(docstring const & str, docstring::value_type chr)
 }
 
 
+int count_bin_chars(string const & str)
+{
+       QString const qstr = toqstr(str).simplified();
+       int count = 0;
+       QString::const_iterator cit = qstr.begin();
+       QString::const_iterator end = qstr.end();
+       for (; cit != end; ++cit)  {
+               switch (cit->category()) {
+               case QChar::Separator_Line:
+               case QChar::Separator_Paragraph:
+               case QChar::Other_Control:
+               case QChar::Other_Format:
+               case QChar::Other_Surrogate:
+               case QChar::Other_PrivateUse:
+               case QChar::Other_NotAssigned:
+                       ++count;
+                       break;
+               default:
+                       break;
+               }
+       }
+       return count;
+}
+
+
 docstring const trim(docstring const & a, char const * p)
 {
        LASSERT(p, return a);

diff --git a/src/support/lstrings.h b/src/support/lstrings.h
index 02b5cf2f2b3e32b54b48101689e713edacf13261..0d21e954a4308600bce39a3e81dc469256fc32c9 100644 (file)
--- a/src/support/lstrings.h
+++ b/src/support/lstrings.h
@@ -199,6 +199,14 @@ int count_char(std::string const & str, char chr);
 /// Count all occurences of char \a chr inside \a str
 int count_char(docstring const & str, docstring::value_type chr);
 
+/** Count all occurences of binary chars inside \a str.
+    It is assumed that \a str is utf-8 encoded and that a binary char
+    belongs to the unicode class names Zl, Zp, Cc, Cf, Cs, Co, or Cn
+    (excluding white space characters such as '\t', '\n', '\v', '\f', '\r').
+    See http://www.unicode.org/Public/6.2.0/ucd/UnicodeData.txt
+*/
+int count_bin_chars(std::string const & str);
+
 /** Trims characters off the end and beginning of a string.
     \code
     trim("ccabccc", "c") == "ab".