Merge pull request #108 from Herringway/slicebuilder-fixes

make SliceBuilder safer to use.
merged-on-behalf-of: BBasile <BBasile@users.noreply.github.com>

source/dyaml/reader.d

@@ -531,15 +531,17 @@ public:
     /// end of the slice being built, the slice is extended (trivial operation).
     ///
     /// See_Also: begin
-    void write(char[] str) @trusted pure nothrow @nogc
+    void write(char[] str) @safe pure nothrow @nogc
     {
         assert(inProgress, "write called without begin");
         assert(end_ <= reader_.bufferOffset_,
                "AT START: Slice ends after buffer position");
 
+        // Nothing? Already done.
+        if (str.length == 0) { return; }
         // If str starts at the end of the slice (is a string returned by a Reader
         // method), just extend the slice to contain str.
-        if(str.ptr == reader_.buffer_.ptr + end_)
+        if(&str[0] == &reader_.buffer_[end_])
         {
             end_ += str.length;
         }
@@ -547,8 +549,7 @@ public:
         // by a Reader method and point to buffer. So we need to memmove.
         else
         {
-            core.stdc.string.memmove(reader_.buffer_.ptr + end_, cast(char*)str.ptr,
+            copy(str, reader_.buffer_[end_..end_ + str.length * char.sizeof]);
-                                     str.length * char.sizeof);
             end_ += str.length;
         }
     }
@@ -585,7 +586,7 @@ public:
     /// position = Position to insert the character at in code units, not code points.
     ///            Must be less than slice length(); a previously returned length()
     ///            can be used.
-    void insert(const dchar c, const size_t position) @system pure nothrow @nogc
+    void insert(const dchar c, const size_t position) @safe pure nothrow @nogc
     {
         assert(inProgress, "insert called without begin");
         assert(start_ + position <= end_, "Trying to insert after the end of the slice");
@@ -600,9 +601,8 @@ public:
 
         if(movedLength > 0)
         {
-            core.stdc.string.memmove(reader_.buffer_.ptr + point + bytes,
+            copy(reader_.buffer_[point..point + movedLength * char.sizeof],
-                                     reader_.buffer_.ptr + point,
+                    reader_.buffer_[point + bytes..point + bytes + movedLength * char.sizeof]);
-                                     movedLength * char.sizeof);
         }
         reader_.buffer_[point .. point + bytes] = encodeBuf[0 .. bytes];
         end_ += bytes;
@@ -635,9 +635,9 @@ public:
         /// ended either by commit()-ing or reverting through the destructor.
         ///
         /// Saves the current state of a slice.
-        this(ref SliceBuilder builder) @system pure nothrow @nogc
+        this(SliceBuilder* builder) @safe pure nothrow @nogc
         {
-            builder_ = &builder;
+            builder_ = builder;
             stackLevel_ = builder_.endStackUsed_;
             builder_.push();
         }

source/dyaml/scanner.d

@@ -1210,7 +1210,7 @@ final class Scanner
         /// Scan a block scalar token with specified style.
         ///
         /// In case of an error, error_ is set. Use throwIfError() to handle this.
-        Token scanBlockScalar(const ScalarStyle style) @trusted
+        Token scanBlockScalar(const ScalarStyle style) @safe
         {
             const startMark = reader_.mark;
 
@@ -1233,7 +1233,7 @@ final class Scanner
             alias Transaction = SliceBuilder.Transaction;
             // Used to strip the last line breaks written to the slice at the end of the
             // scalar, which may be needed based on chomping.
-            Transaction breaksTransaction = Transaction(reader_.sliceBuilder);
+            Transaction breaksTransaction = Transaction(&reader_.sliceBuilder);
             // Read the first indentation/line breaks before the scalar.
             size_t startLen = reader_.sliceBuilder.length;
             if(increment == int.min)
@@ -1263,7 +1263,7 @@ final class Scanner
 
                 // This transaction serves to rollback data read in the
                 // scanBlockScalarBreaksToSlice() call.
-                breaksTransaction = Transaction(reader_.sliceBuilder);
+                breaksTransaction = Transaction(&reader_.sliceBuilder);
                 startLen = reader_.sliceBuilder.length;
                 // The line breaks should actually be written _after_ the if() block
                 // below. We work around that by inserting
@@ -1712,7 +1712,7 @@ final class Scanner
         /// Scan plain scalar token (no block, no quotes).
         ///
         /// In case of an error, error_ is set. Use throwIfError() to handle this.
-        Token scanPlain() @trusted
+        Token scanPlain() @safe
         {
             // We keep track of the allowSimpleKey_ flag here.
             // Indentation rules are loosed for the flow context
@@ -1788,7 +1788,7 @@ final class Scanner
                 endMark = reader_.mark;
 
                 spacesTransaction.commit();
-                spacesTransaction = Transaction(reader_.sliceBuilder);
+                spacesTransaction = Transaction(&reader_.sliceBuilder);
 
                 const startLength = reader_.sliceBuilder.length;
                 scanPlainSpacesToSlice(startMark);
@@ -1809,7 +1809,7 @@ final class Scanner
         ///
         /// Assumes that the caller is building a slice in Reader, and puts the spaces
         /// into that slice.
-        void scanPlainSpacesToSlice(const Mark startMark) @system
+        void scanPlainSpacesToSlice(const Mark startMark) @safe
         {
             // The specification is really confusing about tabs in plain scalars.
             // We just forbid them completely. Do not use tabs in YAML!
@@ -1847,7 +1847,7 @@ final class Scanner
             bool extraBreaks = false;
 
             alias Transaction = SliceBuilder.Transaction;
-            auto transaction = Transaction(reader_.sliceBuilder);
+            auto transaction = Transaction(&reader_.sliceBuilder);
             if(lineBreak != '\n') { reader_.sliceBuilder.write(lineBreak); }
             while(search.canFind(reader_.peek()))
             {