Allow Diff algorithms (patience, histogram) other than default to be …

…applied to folder comparisons (4)

Src/CompareEngines/Wrap_DiffUtils.cpp

@@ -271,7 +271,7 @@ bool DiffUtils::Diff2Files(struct change ** diffs, int depth,
 		if (m_pOptions->m_diffAlgorithm != DIFF_ALGORITHM_DEFAULT)
 		{
 			const unsigned xdl_flags = make_xdl_flags(*m_pOptions);
-			*diffs = diff_2_files_xdiff(m_inf, bin_status, 0, xdl_flags);
+			*diffs = diff_2_files_xdiff(m_inf, bin_status, bMovedBlocks, bin_file, xdl_flags);
 			files[0] = m_inf[0];
 			files[1] = m_inf[1];
 		}

Src/DiffTextBuffer.cpp

@@ -414,7 +414,7 @@ int CDiffTextBuffer::SaveToFile (const String& pszFileName,
 	if (bTempFile)
 	{
 		file.SetUnicoding(ucr::UTF8);
-		file.SetBom(GetOptionsMgr()->GetInt(OPT_CMP_DIFF_ALGORITHM) == 0);
+		file.SetBom(true);
 		bOpenSuccess = !!file.OpenCreate(pszFileName);
 	}
 	else

Src/DiffWrapper.cpp

@@ -892,7 +892,8 @@ bool CDiffWrapper::Diff2Files(struct change ** diffs, DiffFileData *diffData,
 		if (m_options.m_diffAlgorithm != DIFF_ALGORITHM_DEFAULT)
 		{
 			const unsigned xdl_flags = make_xdl_flags(m_options);
-			*diffs = diff_2_files_xdiff(diffData->m_inf, bin_status, (m_pMovedLines[0] != nullptr), xdl_flags);
+			*diffs = diff_2_files_xdiff(diffData->m_inf, bin_status,
+				(m_pMovedLines[0] != nullptr), bin_file, xdl_flags);
 			files[0] = diffData->m_inf[0];
 			files[1] = diffData->m_inf[1];
 		}

Src/xdiff_gnudiff_compat.cpp

@@ -70,7 +70,7 @@ static int hunk_func(long start_a, long count_a, long start_b, long count_b, voi
 	return 0;
 }
 
-struct change * diff_2_files_xdiff (struct file_data filevec[], int* bin_status, int bMoved_blocks_flag, unsigned xdl_flags)
+struct change * diff_2_files_xdiff (struct file_data filevec[], int* bin_status, int bMoved_blocks_flag, int* bin_file, unsigned xdl_flags)
 {
 	mmfile_t mmfile1 = { 0 }, mmfile2 = { 0 };
 	change *script = nullptr;
@@ -79,46 +79,118 @@ struct change * diff_2_files_xdiff (struct file_data filevec[], int* bin_status,
 	xpparam_t xpp = { 0 };
 	xdemitconf_t xecfg = { 0 };
 	xdemitcb_t ecb = { 0 };
-	int bin_flag = 0;
 
-	read_files(filevec, no_details_flag & ~ignore_some_changes, &bin_flag);
+	if (read_files(filevec, no_details_flag & ~ignore_some_changes, bin_file))
+	{
+		int i;
+		int changes;
+		// copy from analyze.c
+		//  We can now safely assume to have a pair of Binary files.
+
+		// Are both files Open and Regular (no Pipes, Directories, Devices (e.g. NUL))
+		if (filevec[0].desc < 0 || filevec[1].desc < 0 ||
+			!(S_ISREG (filevec[0].stat.st_mode)) || !(S_ISREG (filevec[1].stat.st_mode))   )
+			changes = 1;
+		else
+		//  Files with different lengths must be different.  
+		if (filevec[0].stat.st_size != filevec[1].stat.st_size)
+			changes = 1;
+		else
+		//  Identical descriptor implies identical files
+		if (filevec[0].desc == filevec[1].desc)
+			changes = 0;
+		//  Scan both files, a buffer at a time, looking for a difference.  
+		else
+		{
+			//  Same-sized buffers for both files were allocated in read_files().  
+			size_t buffer_size = filevec[0].bufsize;
+
+			for (;;)
+			{
+				//  Read a buffer's worth from both files.  
+				for (i = 0; i < 2; i++)
+					while (filevec[i].buffered_chars < buffer_size)
+					  {
+						int r = _read (filevec[i].desc,
+									   filevec[i].buffer	+ filevec[i].buffered_chars,
+									   (int)(buffer_size - filevec[i].buffered_chars));
+						if (r == 0)
+							break;
+						if (r < 0)
+							pfatal_with_name (filevec[i].name);
+						filevec[i].buffered_chars += r;
+					  }
+
+				//  If the buffers have different number of chars, the files differ.  
+				if (filevec[0].buffered_chars != filevec[1].buffered_chars)
+				{
+					changes = 1;
+					break;
+				}
 
-	mmfile1.ptr = const_cast<char*>(filevec[0].prefix_end);
-	mmfile1.size = static_cast<long>(filevec[0].suffix_begin - filevec[0].prefix_end) - filevec[0].missing_newline;
-	mmfile2.ptr = const_cast<char*>(filevec[1].prefix_end);
-	mmfile2.size = static_cast<long>(filevec[1].suffix_begin - filevec[1].prefix_end) - filevec[1].missing_newline;
+				//  If we reach end-of-file, the files are the same.  
+				if (filevec[0].buffered_chars==0) // therefore: filevec[1].buffered_chars==0
+				{
+					changes = 0;
+					break;
+				}	
 
-	xpp.flags = xdl_flags;
-	xecfg.hunk_func = hunk_func;
-	if (xdl_diff_modified(&mmfile1, &mmfile2, &xpp, &xecfg, &ecb, &xe, &xscr) == 0)
+				//	If buffers have different contents, the files are different.
+				if (memcmp (filevec[0].buffer,
+							filevec[1].buffer,
+							filevec[0].buffered_chars) != 0)
+				{
+					changes = 1;
+					break;
+				}
+
+				//	Files appear identical so far...
+				//	Prepare to loop again for the next pair of buffers.
+				filevec[0].buffered_chars = filevec[1].buffered_chars = 0;
+			}
+		}
+		if (bin_status != NULL)
+			*bin_status = (changes != 0 ? -1 : 1);
+	}
+	else
 	{
-		change *prev = nullptr;
-		for (xdchange_t* xcur = xscr; xcur; xcur = xcur->next)
+		mmfile1.ptr = const_cast<char*>(filevec[0].prefix_end);
+		mmfile1.size = static_cast<long>(filevec[0].suffix_begin - filevec[0].prefix_end) - filevec[0].missing_newline;
+		mmfile2.ptr = const_cast<char*>(filevec[1].prefix_end);
+		mmfile2.size = static_cast<long>(filevec[1].suffix_begin - filevec[1].prefix_end) - filevec[1].missing_newline;
+
+		xpp.flags = xdl_flags;
+		xecfg.hunk_func = hunk_func;
+		if (xdl_diff_modified(&mmfile1, &mmfile2, &xpp, &xecfg, &ecb, &xe, &xscr) == 0)
 		{
-			change* e = static_cast<change*>(malloc(sizeof(change)));
-			if (!e)
-				goto abort;
-			if (!script)
-				script = e;
-			e->line0 = xcur->i1;
-			e->line1 = xcur->i2;
-			e->deleted = xcur->chg1;
-			e->inserted = xcur->chg2;
-			e->match0 = -1;
-			e->match1 = -1;
-			e->trivial = static_cast<char>(xcur->ignore);
-			e->link = nullptr;
-			e->ignore = 0;
-			if (prev)
-				prev->link = e;
-			prev = e;
-		}
+			change *prev = nullptr;
+			for (xdchange_t* xcur = xscr; xcur; xcur = xcur->next)
+			{
+				change* e = static_cast<change*>(malloc(sizeof(change)));
+				if (!e)
+					goto abort;
+				if (!script)
+					script = e;
+				e->line0 = xcur->i1;
+				e->line1 = xcur->i2;
+				e->deleted = xcur->chg1;
+				e->inserted = xcur->chg2;
+				e->match0 = -1;
+				e->match1 = -1;
+				e->trivial = static_cast<char>(xcur->ignore);
+				e->link = nullptr;
+				e->ignore = 0;
+				if (prev)
+					prev->link = e;
+				prev = e;
+			}
 
-		if (bMoved_blocks_flag)
-			moved_block_analysis(&script, filevec);
+			if (bMoved_blocks_flag)
+				moved_block_analysis(&script, filevec);
 
-		xdl_free_script(xscr);
-		xdl_free_env(&xe);
+			xdl_free_script(xscr);
+			xdl_free_env(&xe);
+		}
 	}
 
 	return script;

Src/xdiff_gnudiff_compat.h

@@ -2,4 +2,4 @@
 
 class DiffutilsOptions;
 unsigned long make_xdl_flags(const DiffutilsOptions& options);
-struct change * diff_2_files_xdiff(struct file_data filevec[], int* bin_status, int bMoved_blocks_flag, unsigned xdl_flags);
+struct change * diff_2_files_xdiff(struct file_data filevec[], int* bin_status, int bMoved_blocks_flag, int* bin_file, unsigned xdl_flags);