msAppendSymbol causes memory leak

[szigeti]

msAppendSymbol() should append a symbolObj to a symbolSetObj. The function calls msGrowSymbolSet(), which already allocates memory for a symbolObj instance at symbolset->symbol[symbolset->numsymbols-1]. But msAppendSymbol immediately overwrites this pointer with the pointer to the inserted symbolObj. So the memory allocated to symbolset->symbol[symbolset->numsymbols-1] by msGrowSymbolSet() will never be freed.

Possible solutions:

• free the memory allocated by msGrowSymbolSet() before inserting the new symbolObj.
• copy by value
• do not use msAppendSymbol (unfortunately mapscript uses it..)