How Visual SourceSafe's Merge Process Works

• Microsoft Visual SourceSafe, 16-bit and 32-bit, for Windows, versions 4.0, 4.0a
• Microsoft Visual SourceSafe, 32-bit, for Windows, version 5.0

SUMMARY

This article explains how the merge process works in Visual SourceSafe. The merge process requires three files: an original, and two modified versions of the original. During the merge process, Visual SourceSafe makes two comparisons: one between the original file and the first modified version, and another between the original file and the second modified version. If a change is made in only one file, the change is inserted into the merged file. If there are changes in both files in the same location, then a conflict exists. The user must resolve a conflict manually.

MORE INFORMATION

The first file is a snapshot of the file at the point it was branched. This file is maintained by Visual SourceSafe. The second and third files are the current versions of the original file that are located in the two branches that you want to merge, for example:

Branch1     Branch2
-------     -------

 A           A
 B           B
 C           D
 D           E
 E

To understand how the merge process works, assume that the file looked like the following when it was branched:

Original

A B C D E

If you merge Branch1 into Branch2, the result is as follows:

Branch1     Branch2
-------     -------

 A           A
 B           B
 C           D
 D           E
 E

If you merge Branch2 into Branch1, the result is as follows:

Branch1      Branch2
-------      -------

 A            A
 B            B
 D            D
 E            E

Note that Visual SourceSafe assumes incremental changes were made to both of the changed files. When you merge files that are entirely different, you might get unexpected results.

REFERENCES

"Microsoft Visual SourceSafe User's Guide," versions 4 and 5, Chapter 6.