add #touch processor

4 files changed, 22 insertions, 4 deletions

diff --git a/patchtree/config.py b/patchtree/config.py
index 065b03c..79e82dc 100644
--- a/patchtree/config.py
+++ b/patchtree/config.py
@@ -11,6 +11,7 @@ DEFAULT_PROCESSORS: dict[str, type[Process]] = {
     "jinja": ProcessJinja2,
     "cocci": ProcessCoccinelle,
     "smpl": ProcessCoccinelle,
+    "touch": ProcessTouch,
 }
 
 DEFAULT_DIFFS: dict[str, type[Diff]] = {
diff --git a/patchtree/context.py b/patchtree/context.py
index 2721f9b..c864307 100644
--- a/patchtree/context.py
+++ b/patchtree/context.py
@@ -43,7 +43,11 @@ class DiskFS(FS):
         here = self.path.joinpath(file)
         if not here.exists():
             return None
-        return here.read_bytes().decode()
+        bytes = here.read_bytes()
+        try:
+            return bytes.decode()
+        except:
+            return ""
 
     def get_mode(self, file: str) -> int:
         here = self.path.joinpath(file)
@@ -83,7 +87,11 @@ class ZipFS(FS):
         info = self.get_info(file)
         if info is None:
             return None
-        return self.zip.read(info).decode()
+        bytes = self.zip.read(info)
+        try:
+            return bytes.decode()
+        except:
+            return ""
 
     def get_mode(self, file: str) -> int:
         info = self.get_info(file)
diff --git a/patchtree/diff.py b/patchtree/diff.py
index a3442ae..9712f77 100644
--- a/patchtree/diff.py
+++ b/patchtree/diff.py
@@ -33,11 +33,15 @@ class Diff:
         """
         a = self.a
         b = self.b
-        fromfile = f"a/{self.file}"
-        tofile = f"b/{self.file}"
+
+        if a == b:
+            return ""
 
         assert (a.content or b.content) is not None
 
+        fromfile = f"a/{self.file}"
+        tofile = f"b/{self.file}"
+
         delta = f"diff --git {fromfile} {tofile}\n"
 
         if a.content is None:
diff --git a/patchtree/process.py b/patchtree/process.py
index a44886d..3ac47b1 100644
--- a/patchtree/process.py
+++ b/patchtree/process.py
@@ -72,3 +72,8 @@ class ProcessCoccinelle(Process):
         temp_sp.unlink()
 
         return b
+
+
+class ProcessTouch(Process):
+    def transform(self, a, b):
+        return DiffFile(content=a.content, mode=b.mode)