Fixed a buffer overrun

src/format.cc

@@ -335,8 +335,13 @@ string format_t::truncate(const unistring& ustr, std::size_t width,
 
 	if (newlen > width) {
 	  unistring temp(*i);
+	  if (temp.length() > static_cast<std::size_t>(account_abbrev_length)) {
 	    result << temp.extract(0, account_abbrev_length) << ":";
 	    newlen -= temp.length() - account_abbrev_length;
+	  } else {
+	    result << temp.extract() << ":";
+	    newlen -= temp.length();
+	  }
 	} else {
 	  result << *i << ":";
 	}
@@ -346,7 +351,8 @@ string format_t::truncate(const unistring& ustr, std::size_t width,
 	// Even abbreviated its too big to show the last account, so
 	// abbreviate all but the last and truncate at the beginning.
 	unistring temp(result.str());
-	buf << ".." << temp.extract(temp.length() - width - 2, width - 2);
+	assert(temp.length() > width - 2);
+	buf << ".." << temp.extract(temp.length() - (width - 2), width - 2);
       } else {
 	buf << result.str();
       }

src/unistring.h

@@ -48,6 +48,8 @@
 
 #include "utils.h"
 
+namespace ledger {
+
 /**
  * @class unistring
  *
@@ -68,7 +70,7 @@ public:
     const char * p   = input.c_str();
     std::size_t	 len = input.length();
 
-    //assert(utf8::is_valid(p, p + len));
+    assert(utf8::is_valid(p, p + len));
     utf8::utf8to32(p, p + len, std::back_inserter(utf32chars));
   }
   ~unistring() {
@@ -83,8 +85,13 @@ public:
 		      const std::size_t len   = 0) const
   {
     std::string utf8result;
+    std::size_t this_len = length();
+    assert(begin <= this_len);
+    assert(begin + len <= this_len);
+    if (this_len)
       utf8::utf32to8(utf32chars.begin() + begin,
-		   utf32chars.begin() + begin + (len ? len : length()),
+		     utf32chars.begin() + begin +
+		     (len ? (len > this_len ? this_len : len) : this_len),
 		     std::back_inserter(utf8result));
     return utf8result;
   }
@@ -108,4 +115,6 @@ inline void justify(std::ostream&      out,
     out << str;
 }
 
+} // namespace ledger
+
 #endif // _UNISTRING_H

test/baseline/opt-anon.test

@@ -4,8 +4,8 @@ reg --anon
     Assets:Investments:Vanguard:VMMXX  0.350 VMMXX @ $1.00
     Income:Dividends:Vanguard:VMMXX        $-0.35
 >>>1
-07-Feb-02 6a93dcb30aa7722e967.. ..8000cfb2807d6a978b43  0.350 VMMXX  0.350 VMMXX
+07-Feb-02 6a93dcb30aa7722e967.. ..cfb2807d6a978b431fc7  0.350 VMMXX  0.350 VMMXX
-                                ..b52e4fbac0065bfcc300       $-0.35       $-0.35
+                                ..4fbac0065bfcc300a24e       $-0.35       $-0.35
                                                                      0.350 VMMXX
 >>>2
 === 0