patch: support [FILE [PATCH]] arguments.

POSIX only mentions -i/stdin, but GNU patch -- and Larry Wall's patch 1.3,
found via https://en.wikipedia.org/wiki/Patch_(Unix) -- also support
supplying the name of the file to patch and the name of the patch file
as optional arguments.

The AOSP build makes use of this syntax to patch snakeyaml to remove
references to java.beans.* stuff.

1 files changed, 18 insertions, 7 deletions

diff --git a/toys/posix/patch.c b/toys/posix/patch.c
index 3234a1f0..27c25143 100644
--- a/toys/posix/patch.c
+++ b/toys/posix/patch.c
@@ -15,20 +15,19 @@
  *
  * -E remove empty files --remove-empty-files
  * -F fuzz (number, default 2)
- * [file] which file to patch
 
-USE_PATCH(NEWTOY(patch, "(no-backup-if-mismatch)(dry-run)"USE_TOYBOX_DEBUG("x")"g#fulp#d:i:Rs(quiet)", TOYFLAG_USR|TOYFLAG_BIN))
+USE_PATCH(NEWTOY(patch, ">2(no-backup-if-mismatch)(dry-run)"USE_TOYBOX_DEBUG("x")"g#fulp#d:i:Rs(quiet)", TOYFLAG_USR|TOYFLAG_BIN))
 
 config PATCH
   bool "patch"
   default y
   help
-    usage: patch [-d DIR] [-i file] [-p depth] [-Rlsu] [--dry-run]
+    usage: patch [-d DIR] [-i PATCH] [-p depth] [-Rlsu] [--dry-run] [FILE [PATCH]]
 
     Apply a unified diff to one or more files.
 
     -d	Modify files in DIR
-    -i	Input file (default=stdin)
+    -i	Input patch file (default=stdin)
     -l	Loose match (ignore whitespace)
     -p	Number of '/' to strip from start of file paths (default=all)
     -R	Reverse patch
@@ -267,7 +266,7 @@ char *unquote_file(char *filename) {
       } else {
         ch = unescape(s[1]);
         *t++ = ch ? ch : s[1];
-		s++;
+        s++;
       }
     } else *t++ = *s;
   }
@@ -288,6 +287,7 @@ void patch_main(void)
   int reverse = FLAG(R), state = 0, patchlinenum = 0, strip = 0;
   char *oldname = NULL, *newname = NULL;
 
+  if (toys.optc == 2) TT.i = toys.optargs[1];
   if (TT.i) TT.filepatch = xopenro(TT.i);
   TT.filein = TT.fileout = -1;
 
@@ -388,12 +388,23 @@ void patch_main(void)
         oldsum = TT.oldline + TT.oldlen;
         newsum = TT.newline + TT.newlen;
 
+        // If an original file was provided on the command line, it overrides
+        // *all* files mentioned in the patch, not just the first.
+        if (toys.optc) {
+          char **which = reverse ? &oldname : &newname;
+
+          free(*which);
+          *which = strdup(toys.optargs[0]);
+          // The supplied path should be taken literally with or without -p.
+          toys.optflags |= FLAG_p;
+          TT.p = 0;
+        }
+
         name = reverse ? oldname : newname;
 
         // We're deleting oldname if new file is /dev/null (before -p)
         // or if new hunk is empty (zero context) after patching
-        if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum))
-        {
+        if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum)) {
           name = reverse ? newname : oldname;
           del++;
         }