diff --git a/src/scripts/merge_tools/gitmerge_ort.sh b/src/scripts/merge_tools/gitmerge_ort.sh
index a72d9ee50c..d8a695734b 100755
--- a/src/scripts/merge_tools/gitmerge_ort.sh
+++ b/src/scripts/merge_tools/gitmerge_ort.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s ort"
-if ! "$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-  exit 1
-fi
+"$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/gitmerge_ort_ignorespace.sh b/src/scripts/merge_tools/gitmerge_ort_ignorespace.sh
index a085edcaa6..ef1a5df5f8 100755
--- a/src/scripts/merge_tools/gitmerge_ort_ignorespace.sh
+++ b/src/scripts/merge_tools/gitmerge_ort_ignorespace.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s ort -Xignore-space-change"
-if ! "$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-  exit 1
-fi
+"$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/gitmerge_ort_imports.sh b/src/scripts/merge_tools/gitmerge_ort_imports.sh
index cf0309d91f..eb83295136 100755
--- a/src/scripts/merge_tools/gitmerge_ort_imports.sh
+++ b/src/scripts/merge_tools/gitmerge_ort_imports.sh
@@ -13,5 +13,9 @@ fi
 
 cd "$clone_dir" || exit 1
 if ! "$MERGE_SCRIPTS_DIR"/resolve-import-conflicts; then
+  echo "Conflict"
+  git merge --abort
   exit 1
 fi
+
+exit 0
diff --git a/src/scripts/merge_tools/gitmerge_ort_imports_ignorespace.sh b/src/scripts/merge_tools/gitmerge_ort_imports_ignorespace.sh
index b6ae36b948..41ee46a2e1 100755
--- a/src/scripts/merge_tools/gitmerge_ort_imports_ignorespace.sh
+++ b/src/scripts/merge_tools/gitmerge_ort_imports_ignorespace.sh
@@ -13,5 +13,9 @@ fi
 
 cd "$clone_dir" || exit 1
 if ! "$MERGE_SCRIPTS_DIR"/resolve-import-conflicts; then
+  echo "Conflict"
+  git merge --abort
   exit 1
 fi
+
+exit 0
diff --git a/src/scripts/merge_tools/gitmerge_recursive_histogram.sh b/src/scripts/merge_tools/gitmerge_recursive_histogram.sh
index 3d8238775a..6453c6e00e 100755
--- a/src/scripts/merge_tools/gitmerge_recursive_histogram.sh
+++ b/src/scripts/merge_tools/gitmerge_recursive_histogram.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s recursive -Xdiff-algorithm=histogram"
-if ! "$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-  exit 1
-fi
+"$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/gitmerge_recursive_ignorespace.sh b/src/scripts/merge_tools/gitmerge_recursive_ignorespace.sh
index 519db73d40..812d2dcd18 100755
--- a/src/scripts/merge_tools/gitmerge_recursive_ignorespace.sh
+++ b/src/scripts/merge_tools/gitmerge_recursive_ignorespace.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s recursive -Xignore-space-change"
-if ! "$MERGE_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-    exit 1
-fi
+"$MERGE_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/gitmerge_recursive_minimal.sh b/src/scripts/merge_tools/gitmerge_recursive_minimal.sh
index e5a6edff9f..e7d916539a 100755
--- a/src/scripts/merge_tools/gitmerge_recursive_minimal.sh
+++ b/src/scripts/merge_tools/gitmerge_recursive_minimal.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s recursive -Xdiff-algorithm=minimal"
-if ! "$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-    exit 1
-fi
+"$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/gitmerge_recursive_myers.sh b/src/scripts/merge_tools/gitmerge_recursive_myers.sh
index 3fafe5e977..f95f093ba7 100755
--- a/src/scripts/merge_tools/gitmerge_recursive_myers.sh
+++ b/src/scripts/merge_tools/gitmerge_recursive_myers.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s recursive -Xdiff-algorithm=myers"
-if ! "$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-  exit 1
-fi
+"$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/gitmerge_recursive_patience.sh b/src/scripts/merge_tools/gitmerge_recursive_patience.sh
index ef47dc2cab..77e5a8e449 100755
--- a/src/scripts/merge_tools/gitmerge_recursive_patience.sh
+++ b/src/scripts/merge_tools/gitmerge_recursive_patience.sh
@@ -7,6 +7,4 @@ clone_dir=$1
 branch1=$2
 branch2=$3
 strategy="-s recursive -Xdiff-algorithm=patience"
-if ! "$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"; then
-  exit 1
-fi
+"$MERGE_SCRIPTS_DIR"/gitmerge.sh "$clone_dir" "$branch1" "$branch2" "$strategy"
diff --git a/src/scripts/merge_tools/resolve-conflicts.py b/src/scripts/merge_tools/resolve-conflicts.py
new file mode 100755
index 0000000000..ef1781cea5
--- /dev/null
+++ b/src/scripts/merge_tools/resolve-conflicts.py
@@ -0,0 +1,273 @@
+#! /usr/bin/env python
+
+# This is a helper script for `resolve-adjacent-conflicts` and
+# `resolve-import-conflicts`.
+
+"""Edits a file in place to remove certain conflict markers.
+
+Usage: resolve-conflicts.py [options] <filenme>
+
+--java_imports: Resolves conflicts related to Java import statements
+The output includes every `import` statements that is in either of the parents.
+
+--adjacent_lines: Resolves conflicts on adjacent lines, by accepting both edits.
+
+Exit status is 0 (success) if no conflicts remain.
+Exit status is 1 (failure) if conflicts remain.
+"""
+
+from argparse import ArgumentParser
+import itertools
+import os
+import shutil
+import sys
+import tempfile
+
+arg_parser = ArgumentParser()
+arg_parser.add_argument("filename")
+arg_parser.add_argument(
+    "--java_imports",
+    action="store_true",
+    help="If set, resolve conflicts related to Java import statements",
+)
+arg_parser.add_argument(
+    "--adjacent_lines",
+    action="store_true",
+    help="If set, resolve conflicts on adjacent lines",
+)
+args = arg_parser.parse_args()
+
+# Global variables: `filename` and `lines`.
+
+filename = args.filename
+
+with open(filename) as file:
+    lines = file.readlines()
+
+
+def main():
+    """The main entry point."""
+    # Exit status 0 means no conflicts remain, 1 means some merge conflict remains.
+    conflicts_remain = False
+    with tempfile.NamedTemporaryFile(mode="w", delete=False) as tmp:
+        file_len = len(lines)
+        i = 0
+        while i < file_len:
+            conflict = looking_at_conflict(i, lines)
+            if conflict is None:
+                tmp.write(lines[i])
+                i = i + 1
+            else:
+                (base, parent1, parent2, num_lines) = conflict
+                merged = merge(base, parent1, parent2)
+                if merged is None:
+                    tmp.write(lines[i])
+                    i = i + 1
+                    conflicts_remain = True
+                else:
+                    for line in merged:
+                        tmp.write(line)
+                    i = i + num_lines
+
+        tmp.close()
+        shutil.copy(tmp.name, filename)
+        os.unlink(tmp.name)
+
+    if conflicts_remain:
+        sys.exit(1)
+    else:
+        sys.exit(0)
+
+
+def looking_at_conflict(start_index, lines):  # pylint: disable=R0911
+    """Tests whether the following text starts a conflict.
+    If not, returns None.
+    If so, returns a 4-tuple of (base, parent1, parent2, num_lines_in_conflict)
+    where the first 3 elements of the tuple are lists of lines.
+    """
+
+    if not lines[start_index].startswith("<<<<<<<"):
+        return None
+
+    base = []
+    parent1 = []
+    parent2 = []
+
+    num_lines = len(lines)
+    index = start_index + 1
+    if index == num_lines:
+        return None
+    while not (
+        lines[index].startswith("|||||||") or lines[index].startswith("=======")
+    ):
+        parent1.append(lines[index])
+        index = index + 1
+        if index == num_lines:
+            print(
+                "Starting at line "
+                + start_index
+                + ", did not find ||||||| or ======= in "
+                + filename
+            )
+            return None
+    if lines[index].startswith("|||||||"):
+        index = index + 1
+        if index == num_lines:
+            print("File ends with |||||||: " + filename)
+            return None
+        while not lines[index].startswith("======="):
+            base.append(lines[index])
+            index = index + 1
+            if index == num_lines:
+                print(
+                    "Starting at line "
+                    + start_index
+                    + ", did not find ======= in "
+                    + filename
+                )
+                return None
+    assert lines[index].startswith("=======")
+    index = index + 1  # skip over "=======" line
+    if index == num_lines:
+        print("File ends with =======: " + filename)
+        return None
+    while not lines[index].startswith(">>>>>>>"):
+        parent2.append(lines[index])
+        index = index + 1
+        if index == num_lines:
+            print(
+                "Starting at line "
+                + start_index
+                + ", did not find >>>>>>> in "
+                + filename
+            )
+            return None
+    index = index + 1
+
+    return (base, parent1, parent2, index - start_index)
+
+
+def merge(base, parent1, parent2):
+    """Given text for the base and two parents, return merged text.
+
+    Args:
+        base: a list of lines
+        parent1: a list of lines
+        parent2: a list of lines
+
+    Returns:
+        a list of lines, or None if it cannot do merging.
+    """
+
+    print(base, parent1, parent2)
+
+    if args.java_imports:
+        if (
+            all_import_lines(base)
+            and all_import_lines(parent1)
+            and all_import_lines(parent2)
+        ):
+            # A simplistic merge that retains all import lines in either parent.
+            return list(set(parent1 + parent2)).sort()
+
+    if args.adjacent_lines:
+        adjacent_line_merge = merge_edits_on_different_lines(base, parent1, parent2)
+        if adjacent_line_merge is not None:
+            return adjacent_line_merge
+
+    return None
+
+
+def all_import_lines(lines):
+    """Return true if every given line is a Java import line or is blank."""
+    return all(line.startswith("import ") or line.strip() == "" for line in lines)
+
+
+def merge_edits_on_different_lines(base, parent1, parent2):
+    """Return a merged version, if at most parent1 or parent2 edits each line.
+    Otherwise, return None.
+    """
+
+    print("Entered merge_edits_on_different_lines")
+
+    ### No lines are added or removed, only modified.
+    base_len = len(base)
+    result = None
+    if base_len == len(parent1) and base_len == len(parent2):
+        result = []
+        for base_line, parent1_line, parent2_line in itertools.zip_longest(
+            base, parent1, parent2
+        ):
+            print("Considering line:", base_line, parent1_line, parent2_line)
+            if parent1_line == parent2_line:
+                result.append(parent1_line)
+            elif base_line == parent1_line:
+                result.append(parent2_line)
+            elif base_line == parent2_line:
+                result.append(parent1_line)
+            else:
+                result = None
+                break
+        print("merge_edits_on_different_lines =>", result)
+    if result is not None:
+        print("merge_edits_on_different_lines =>", result)
+        return result
+
+    ### Deletions at the beginning or end.
+    if base_len != 0:
+        result = merge_base_is_prefix_or_suffix(base, parent1, parent2)
+        if result is None:
+            result = merge_base_is_prefix_or_suffix(base, parent2, parent1)
+        if result is not None:
+            return result
+
+    ### Interleaved deletions, with an empty merge outcome.
+    if base_len != 0:
+        if issubsequence(parent1, base) and issubsequence(parent2, base):
+            return []
+
+    print("merge_edits_on_different_lines =>", result)
+    return result
+
+
+def merge_base_is_prefix_or_suffix(base, parent1, parent2):
+    """Special cases when the base is a prefix or suffix of parent1.
+    That is, parent1 is pure additions at the beginning or end of base.  Parent2
+    deleted all the lines, possibly replacing them by something else.  (We know
+    this because there is no common line in base and parent2.  If there were, it
+    would also be in parent1, and the hunk would have been split into two at the
+    common line that's in all three texts.)
+    We know the relative position of the additions in parent1.
+    """
+    base_len = len(base)
+    parent1_len = len(parent1)
+    parent2_len = len(parent2)
+    if base_len < parent1_len:
+        if parent1[:base_len] == base:
+            print("startswith", parent1, base)
+            return parent2 + parent1[base_len:]
+        if parent1[-base_len:] == base:
+            print("endswith", parent1, base)
+            return parent1[:-base_len] + parent2
+    return None
+
+
+def issubsequence(s1, s2):
+    """Returns true if s1 is subsequence of s2."""
+
+    # Iterative implementation.
+
+    n, m = len(s1), len(s2)
+    i, j = 0, 0
+    while i < n and j < m:
+        if s1[i] == s2[j]:
+            i += 1
+        j += 1
+
+    # If i reaches end of s1, we found all characters of s1 in s2,
+    # so s1 is a subsequence of s2.
+    return i == n
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/scripts/merge_tools/resolve-import-conflicts b/src/scripts/merge_tools/resolve-import-conflicts
index fc4605f54a..73db46473d 100755
--- a/src/scripts/merge_tools/resolve-import-conflicts
+++ b/src/scripts/merge_tools/resolve-import-conflicts
@@ -1,17 +1,24 @@
 #!/bin/bash
 # bash, not POSIX sh, because of "readarray".
 
-# This script edits files to remove conflict markers related to Java imports.
-# It works on all files given on the command line;
-# if none are given, it works on all files in or under the current directory.
+# This script edits files in place to remove conflict markers related to Java
+# imports.  For a given conflict that involves only `import` statements and
+# blank lines, the output includes every `import` statement that is in either
+# of the parents.  This script leaves other conflicts untouched.
+
+# Usage:
+#   resolve-import-conflicts [file ...]
+#
+# The script works on all files given on the command line.
+# If none are given, the script works on all files in or under the current directory.
+#
+# The exit status code is 0 (success) if all conflicts are resolved in all the files.
+# The exit status code is 1 (failure) if any conflict remains.
 
 # This script is not a git mergetool.  A git mergetool is given the base, parent 1, and
 # parent 2 files, all without conflict markers.
-# However, this script can be run instead of a git mergetool, or after a git mergetool.
-
-# Exit status is 1 if conflicts remain after running this script or if
-# there is an error generated in some file.
-# Exit status is 0 if there are no conflicts after running this script.
+# However, this can be run after a git mergetool that leaves conflict markers
+# in files, as the default git mergetool does.
 
 if [ "$#" -eq 0 ] ; then
   readarray -t files < <(grep -l -r '^<<<<<<< HEAD' .)
@@ -21,20 +28,12 @@ fi
 
 SCRIPTDIR="$(cd "$(dirname "$0")" && pwd -P)"
 
+status=0
+
 for file in "${files[@]}" ; do
-  if ! "${SCRIPTDIR}"/resolve-import-conflicts-in-file.py "$file" ; then
-    echo "Error in $file"
-    git merge --abort
-    exit 1
+  if ! "${SCRIPTDIR}"/resolve-conflicts.py --java_imports "$file" ; then
+    status=1
   fi
 done
 
-# From https://stackoverflow.com/questions/41246415/
-if git diff --exit-code -S '<<<<<<< HEAD' -S "=======" -S ">>>>>>> $(git name-rev --name-only MERGE_HEAD)" HEAD ; then
-  exit 0
-fi
-
-echo "Conflict"
-git merge --abort
-exit 1
-
+exit $status
diff --git a/src/scripts/merge_tools/resolve-import-conflicts-in-file.py b/src/scripts/merge_tools/resolve-import-conflicts-in-file.py
deleted file mode 100755
index 2398ec4586..0000000000
--- a/src/scripts/merge_tools/resolve-import-conflicts-in-file.py
+++ /dev/null
@@ -1,153 +0,0 @@
-#! /usr/bin/env python
-
-"""Edits a file in place to remove conflict markers related to Java imports.
-The merged version contains all the imports that appear in either parent.
-This is simplistic, but is often adequate.
-
-Exit status is 1 only if the program halts exceptionally.
-With an exit status of 0, some conflicts may still exist in the file.
-"""
-
-
-# TODO: merge both scripts into one.
-
-import os
-import shutil
-import sys
-import tempfile
-
-if len(sys.argv) != 2:
-    print(
-        "resolve-import-conflicts-in-file: Provide exactly one command-line argument."
-    )
-    sys.exit(1)
-
-filename = sys.argv[1]
-with open(filename) as file:
-    lines = file.readlines()
-
-
-def all_import_lines(lines):
-    """Return true if every line is a Java import line."""
-    return all(line.startswith("import ") for line in lines)
-
-
-def merge(base, parent1, parent2):
-    """Given text for the base and two parents, return merged text.
-
-    This currently does a simplistic merge that retains all lines in either parent.
-
-    Args:
-        base: a list of lines
-        parent1: a list of lines
-        parent2: a list of lines
-
-    Returns:
-        a list of lines, or None if it cannot do merging.
-    """
-
-    if (
-        all_import_lines(base)
-        and all_import_lines(parent1)
-        and all_import_lines(parent2)
-    ):
-        return parent1 + parent2
-
-    return None
-
-
-def looking_at_conflict(start_index, lines):  # pylint: disable=R0911
-    """Tests whether the text starting at line `start_index` is the beginning of a conflict.
-    If not, returns None.
-    If so, returns a 4-tuple of (base, parent1, parent2, num_lines_in_conflict)
-    where the first 3 elements of the tuple are lists of lines.
-    Args:
-        start_index: an index into `lines`.
-        lines: all the lines of the file with name `filename`.
-    """
-
-    if not lines[start_index].startswith("<<<<<<<"):
-        return None
-
-    base = []
-    parent1 = []
-    parent2 = []
-
-    num_lines = len(lines)
-    index = start_index + 1
-    if index == num_lines:
-        return None
-    while not (
-        lines[index].startswith("|||||||") or lines[index].startswith("=======")
-    ):
-        parent1.append(lines[index])
-        index = index + 1
-        if index == num_lines:
-            print(
-                "Starting at line "
-                + start_index
-                + ", did not find ||||||| or ======= in "
-                + filename
-            )
-            return None
-    if lines[index].startswith("|||||||"):
-        index = index + 1
-        if index == num_lines:
-            print("File ends with |||||||: " + filename)
-            return None
-        while not lines[index].startswith("======="):
-            base.append(lines[index])
-            index = index + 1
-            if index == num_lines:
-                print(
-                    "Starting at line "
-                    + start_index
-                    + ", did not find ======= in "
-                    + filename
-                )
-                return None
-    assert lines[index].startswith("=======")
-    index = index + 1  # skip over "=======" line
-    if index == num_lines:
-        print("File ends with =======: " + filename)
-        return None
-    while not lines[index].startswith(">>>>>>>"):
-        parent2.append(lines[index])
-        index = index + 1
-        if index == num_lines:
-            print(
-                "Starting at line "
-                + start_index
-                + ", did not find >>>>>>> in "
-                + filename
-            )
-            return None
-    index = index + 1
-
-    return (base, parent1, parent2, index - start_index)
-
-
-## Main starts here.
-
-with tempfile.NamedTemporaryFile(mode="w", delete=False) as tmp:
-    file_len = len(lines)
-    i = 0
-    while i < file_len:
-        conflict = looking_at_conflict(i, lines)
-        if conflict is None:
-            tmp.write(lines[i])
-            i = i + 1
-        else:
-            (base, parent1, parent2, num_lines) = conflict
-            merged = merge(base, parent1, parent2)
-            if merged is None:
-                tmp.write(lines[i])
-                i = i + 1
-            else:
-                for line in merged:
-                    tmp.write(line)
-                i = i + num_lines
-
-    tmp.close()
-    shutil.copy(tmp.name, filename)
-    os.unlink(tmp.name)