From 585c86e2a439d5df23595b249eb28554764ec6b4 Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Sat, 4 Nov 2023 07:19:37 -0700
Subject: [PATCH] Support \n in /zip/.args files

---
 examples/examples.mk   |  1 +
 libc/str/iszipeocd32.c |  3 +++
 tool/args/args.c       | 17 ++++++++++++++++-
 tool/decode/zip.c      | 13 +++++++------
 4 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/examples/examples.mk b/examples/examples.mk
index f8ef55984..fba46f3e0 100644
--- a/examples/examples.mk
+++ b/examples/examples.mk
@@ -93,6 +93,7 @@ EXAMPLES_DIRECTDEPS =								\
 	THIRD_PARTY_VQSORT							\
 	THIRD_PARTY_XED								\
 	THIRD_PARTY_ZLIB							\
+	TOOL_ARGS								\
 	TOOL_BUILD_LIB								\
 	TOOL_VIZ_LIB
 
diff --git a/libc/str/iszipeocd32.c b/libc/str/iszipeocd32.c
index 30925daad..20c368504 100644
--- a/libc/str/iszipeocd32.c
+++ b/libc/str/iszipeocd32.c
@@ -42,6 +42,9 @@ int IsZipEocd32(const uint8_t *p, size_t n, size_t i) {
   if (ZIP_CDIR_RECORDS(p + i) * kZipCfileHdrMinSize > ZIP_CDIR_SIZE(p + i)) {
     return kZipErrorEocdRecordsOverflow;
   }
+  if (ZIP_CDIR_OFFSET(p + i) == 0xFFFFFFFFu) {
+    return kZipErrorEocdRecordsOverflow;
+  }
   if (ckd_add(&offset, ZIP_CDIR_OFFSET(p + i), ZIP_CDIR_SIZE(p + i))) {
     return kZipErrorEocdOffsetSizeOverflow;
   }
diff --git a/tool/args/args.c b/tool/args/args.c
index b9d10593a..5d9db1b81 100644
--- a/tool/args/args.c
+++ b/tool/args/args.c
@@ -38,6 +38,21 @@ static struct ZipArgs {
   char **oldargv;
 } g_zipargs;
 
+// remap \n → newline
+static char *Decode(char *arg) {
+  int i, j;
+  for (i = j = 0; arg[i]; ++i) {
+    if (arg[i] == '\\' && arg[i + 1] == 'n') {
+      arg[j++] = '\n';
+      ++i;
+    } else {
+      arg[j++] = arg[i];
+    }
+  }
+  arg[j] = 0;
+  return arg;
+}
+
 static void AddZipArg(int *argc, char ***argv, char *arg) {
   *argv = xrealloc(*argv, (++(*argc) + 1) * sizeof(*(*argv)));
   (*argv)[*argc - 1] = arg;
@@ -72,7 +87,7 @@ int LoadZipArgsImpl(int *argc, char ***argv, char *data) {
           AddZipArg(&n, &args, (*argv)[i]);
         }
       } else {
-        AddZipArg(&n, &args, arg);
+        AddZipArg(&n, &args, Decode(arg));
       }
       start = 0;
     }
diff --git a/tool/decode/zip.c b/tool/decode/zip.c
index 51b9df1c3..4370a44a0 100644
--- a/tool/decode/zip.c
+++ b/tool/decode/zip.c
@@ -48,6 +48,8 @@
  * @fileoverview Zip File Disassembler.
  */
 
+uint8_t *map;
+
 static __wur char *FormatDosDate(uint16_t dosdate) {
   return xasprintf("%04u-%02u-%02u", ((dosdate >> 9) & 0b1111111) + 1980,
                    (dosdate >> 5) & 0b1111, dosdate & 0b11111);
@@ -60,9 +62,9 @@ static __wur char *FormatDosTime(uint16_t dostime) {
 
 void AdvancePosition(uint8_t *map, size_t *pos, size_t off) {
   if (off > *pos) {
-    printf("\n/\t<%s>\n", "LIMBO");
-    disassemblehex(&map[*pos], off - *pos, stdout);
-    printf("/\t</%s>\n", "LIMBO");
+    /* printf("\n/\t<%s>\n", "LIMBO"); */
+    /* disassemblehex(&map[*pos], off - *pos, stdout); */
+    /* printf("/\t</%s>\n", "LIMBO"); */
   }
   *pos = off;
 }
@@ -288,8 +290,8 @@ void ShowLocalFileHeader(uint8_t *lf, uint16_t idx) {
 }
 
 void ShowCentralFileHeader(uint8_t *cf) {
-  printf("\n/\t%s (%zu %s)\n", "central directory file header",
-         ZIP_CFILE_HDRSIZE(cf), "bytes");
+  printf("\n/\t%s (%zu %s @ %#lx)\n", "central directory file header",
+         ZIP_CFILE_HDRSIZE(cf), "bytes", cf - map);
   show(".ascii", format(b1, "%`'.*s", 4, cf), "magic");
   show(".byte", _gc(xasprintf("%d", ZIP_CFILE_VERSIONMADE(cf))),
        "zip version made");
@@ -485,7 +487,6 @@ void DisassembleZip(const char *path, uint8_t *p, size_t n) {
 
 int main(int argc, char *argv[]) {
   int fd;
-  uint8_t *map;
   struct stat st;
   ShowCrashReports();
   CHECK_EQ(2, argc);