Conflicts and conflict resolution

Conflicts may happen when:

• you change the order of unapplied patches with git gq change-order and then run git gq push

• you unapply patches, make changes in the repository, e.g. git pull and then apply the patches again

• you combine unapplied patches with git gq fold that are not in consecutive order

In the patch file example above, you see after ‘@@ -4,8 +4,8 @@’ a single hunk. The numbers are line numbers in the source file, here ‘sample.c’.

All following lines that are indented with a single space are context lines. Lines that start with a ‘-’ character are to be removed, lines that start with a ‘+’ character are to be added.

A conflict occurs when the context lines or the lines to be removed couldn’t be found. In this case, a reject file is created.

Here are the messages you see in case of a conflict after you ran git gq push:

$ ../../bin/git-gq push
Applying: sample-comment
Checking patch sample.c...
error: while searching for:
  {
    int i;

    printf("number of arguments: %d\n", argc);
    printf("program name: %s\n", argv[0]);
    for(i=1; i<argc; i++)
      printf("arg no %2d: %s\n", i, argv[i]);
    return 0;

error: patch failed: sample.c:4
Applying patch sample.c with 1 reject...
Rejected hunk #1.
Patch failed at 0001 sample-comment
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Fix the change by looking at the *.rej files.
Then run:
  git-gq continue
To abort the operation without fixing run:
  git-gq abort

And here is the content of the reject file, ‘sample.c.rej’ in this case:

diff a/sample.c b/sample.c    (rejected hunks)
@@ -4,8 +4,8 @@ int main(int argc, char *argv[])
   {
     int i;

-    printf("number of arguments: %d\n", argc);
     printf("program name: %s\n", argv[0]);
+    /* iterate over all command line arguments: */
     for(i=1; i<argc; i++)
       printf("arg no %2d: %s\n", i, argv[i]);
     return 0;

In our example here, while the patch was moved to the patch queue, this line:

printf("number of arguments: %d\n", argc);

had been changed to:

printf("My number of arguments: %d\n", argc);

So the line to remove by the patch wasn’t found and we had a conflict. If we open both, the original file ‘sample.c’ and the reject file ‘sample.c.rej’ in any text editor, we can easily see what the patch intended to do and apply the changes manually.

This is called resolving a conflict. You have to go through all reject files, there may be more than one and resolve all conflicts.

After you are finished, run:

git gq continue

This finishes the operation and tells git that the conflict was resolved. You must not run git am continue yourself, git gq continue already does this for you.

If you cannot resolve conflicts because the reject files are too long or complicated, you can abort the last command with:

git gq abort

In this case you may have to compare two versions of files and apply changes directly.