git-apply: applying a patch to make a symlink shorter.

The internal representation of the result is counted string
(i.e. char *buf and ulong size), which is fine for writing out
to regular file, but throwing the buf at symlink(2) was a
no-no.

Reported by Willy Tarreau.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-apply.c b/builtin-apply.c
index f8c6763c7464a01ea81fae0665a7aef50809d031..c15987386b0818b770f40ea92dbded6b25ff394e 100644 (file)
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -1698,6 +1698,14 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
        desc.buffer = buf;
        if (apply_fragments(&desc, patch) < 0)
                return -1;
+
+       /* NUL terminate the result */
+       if (desc.alloc <= desc.size) {
+               desc.buffer = xrealloc(desc.buffer, desc.size + 1);
+               desc.alloc++;
+       }
+       desc.buffer[desc.size] = 0;
+
        patch->result = desc.buffer;
        patch->resultsize = desc.size;
 
@@ -2040,6 +2048,9 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
        int fd;
 
        if (S_ISLNK(mode))
+               /* Although buf:size is counted string, it also is NUL
+                * terminated.
+                */
                return symlink(buf, path);
        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
        if (fd < 0)

diff --git a/t/t4115-apply-symlink.sh b/t/t4115-apply-symlink.sh
new file mode 100755 (executable)
index 0000000..d5f2cfb
--- /dev/null
+++ b/t/t4115-apply-symlink.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+#
+
+test_description='git-apply symlinks and partial files
+
+'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+
+       ln -s path1/path2/path3/path4/path5 link1 &&
+       git add link? &&
+       git commit -m initial &&
+
+       git branch side &&
+
+       rm -f link? &&
+
+       ln -s htap6 link1 &&
+       git update-index link? &&
+       git commit -m second &&
+
+       git diff-tree -p HEAD^ HEAD >patch  &&
+       git apply --stat --summary patch
+
+'
+
+test_expect_success 'apply symlink patch' '
+
+       git checkout side &&
+       git apply patch &&
+       git diff-files -p >patched &&
+       diff -u patch patched
+
+'
+
+test_expect_success 'apply --index symlink patch' '
+
+       git checkout -f side &&
+       git apply --index patch &&
+       git diff-index --cached -p HEAD >patched &&
+       diff -u patch patched
+
+'
+
+test_done