Rando Jones

Affects version 14w28a as well.

Using code from MCP 9.08 for MC1.7.10 I've been able to correct this in my personal mod with the following changes:

blocks/BlockFence.java

public void addCollisionBoxesToList(World par1, int par2, int par3, int par4, AxisAlignedBB par5, List par6, Entity par7)
    {
        boolean var8 = this.func_149826_e(par1, par2, par3, par4 - 1) && (!(par1.getBlock(par2, par3, par4 - 1) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2, par3, par4 - 1) & 1) == 1);
        boolean var9 = this.func_149826_e(par1, par2, par3, par4 + 1) && (!(par1.getBlock(par2, par3, par4 + 1) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2, par3, par4 + 1) & 1) == 1);
        boolean var10 = this.func_149826_e(par1, par2 - 1, par3, par4) && (!(par1.getBlock(par2 - 1, par3, par4) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2 - 1, par3, par4) & 1) == 0);
        boolean var11 = this.func_149826_e(par1, par2 + 1, par3, par4) && (!(par1.getBlock(par2 + 1, par3, par4) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2 + 1, par3, par4) & 1) == 0);
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    public void setBlockBoundsBasedOnState(IBlockAccess par1, int par2, int par3, int par4)
    {
        boolean var5 = this.func_149826_e(par1, par2, par3, par4 - 1) && (!(par1.getBlock(par2, par3, par4 - 1) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2, par3, par4 - 1) & 1) == 1);
        boolean var6 = this.func_149826_e(par1, par2, par3, par4 + 1) && (!(par1.getBlock(par2, par3, par4 + 1) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2, par3, par4 + 1) & 1) == 1);
        boolean var7 = this.func_149826_e(par1, par2 - 1, par3, par4) && (!(par1.getBlock(par2 - 1, par3, par4) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2 - 1, par3, par4) & 1) == 0);
        boolean var8 = this.func_149826_e(par1, par2 + 1, par3, par4) && (!(par1.getBlock(par2 + 1, par3, par4) instanceof BlockFenceGate) || (par1.getBlockMetadata(par2 + 1, par3, par4) & 1) == 0);
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   public boolean func_149826_e(IBlockAccess par1, int par2, int par3, int par4)
    {
        Block var5 = par1.getBlock(par2, par3, par4);
        
        boolean ret = (var5 == this);
        if (!ret)
        {
	        if (var5 instanceof BlockFence)
	        {
	        	ret = this.blockMaterial == var5.blockMaterial;
	        }
	        else if (var5 instanceof BlockFenceGate)
	        {
	        	ret = true;
	        }
	        else if (var5.blockMaterial.isOpaque() && var5.renderAsNormalBlock())
	        {
	        	ret = var5.blockMaterial != Material.field_151572_C; //don't connect to melons or pumpkins
	        	ret = ret && var5 != Blocks.hay_block;
	        }
        }
        else //always connect to self
        {
        	ret = true;
        }
        
        return ret;
    }

client/renderer/RenderBlocks.java

public boolean renderBlockFence(BlockFence par1, int par2, int par3, int par4)
    {
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				Block nearBlock = null;

        if (par1.func_149826_e(this.blockAccess, par2 - 1, par3, par4) || par1.func_149826_e(this.blockAccess, par2 + 1, par3, par4))
        {
            if (!(this.blockAccess.getBlock(par2 - 1, par3, par4) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2 - 1, par3, par4) & 1) == 0)
            {
            	var8 = true;
            }
            else if (!(this.blockAccess.getBlock(par2 + 1, par3, par4) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2 + 1, par3, par4) & 1) == 0)
            {
            	var8 = true;
            }
        }

        if (par1.func_149826_e(this.blockAccess, par2, par3, par4 - 1) || par1.func_149826_e(this.blockAccess, par2, par3, par4 + 1))
        {
            if (!(this.blockAccess.getBlock(par2, par3, par4 - 1) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2, par3, par4 - 1) & 1) == 1)
            {
            	var9 = true;
            }
            else if (!(this.blockAccess.getBlock(par2, par3, par4 + 1) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2, par3, par4 + 1) & 1) == 1)
            {
            	var9 = true;
            }
				}

        boolean var10 = par1.func_149826_e(this.blockAccess, par2 - 1, par3, par4) && (!(this.blockAccess.getBlock(par2 - 1, par3, par4) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2 - 1, par3, par4) & 1) == 0);
        boolean var11 = par1.func_149826_e(this.blockAccess, par2 + 1, par3, par4) && (!(this.blockAccess.getBlock(par2 + 1, par3, par4) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2 + 1, par3, par4) & 1) == 0); 
        boolean var12 = par1.func_149826_e(this.blockAccess, par2, par3, par4 - 1) && (!(this.blockAccess.getBlock(par2, par3, par4 - 1) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2, par3, par4 - 1) & 1) == 1);
        boolean var13 = par1.func_149826_e(this.blockAccess, par2, par3, par4 + 1) && (!(this.blockAccess.getBlock(par2, par3, par4 + 1) instanceof BlockFenceGate) || (this.blockAccess.getBlockMetadata(par2, par3, par4 + 1) & 1) == 1);
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Sorry to dump this on you - I hope your open to coding changes with actual code examples. I just made a suggestion in reddit/minecraftSuggestions about this very issue.

This same code can be used to fix BlockWall as well.

Note that changes to BlockFence.java/func_149826_e contain some alterations to make fences not connect to melons or hay blocks; exclude that at your preference.

Yes, this is still an issue in 14w05a, for hoes at least (I just checked it).

Hoes don't play a break sound when you use up the last point of their durability (0 of x points left) tilling dirt. Other tools (pickaxe, shovel, axe, sword, ...) don't play a break sound or break animation when using the last of their durability attacking a mob, but do both when breaking blocks with them.