commit: allow editing the commit message even in shared repos

It was pointed out by Yaroslav Halchenko that the file containing the
commit message is writable only by the owner, which means that we have
to rewrite it from scratch in a shared repository.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/commit.c b/builtin/commit.c
index f2a8b78c7a7c5f52c46e03e644cf50413b643d3e..ce11a17f8ac51f4f9045db419ea2c253524cf078 100644 (file)
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -761,7 +761,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
                hook_arg2 = "";
        }
 
-       s->fp = fopen(git_path(commit_editmsg), "w");
+       s->fp = fopen_for_writing(git_path(commit_editmsg));
        if (s->fp == NULL)
                die_errno(_("could not open '%s'"), git_path(commit_editmsg));
 

diff --git a/git-compat-util.h b/git-compat-util.h
index 0feeae298340afbe22276ce595de4a6cba397926..d98f3af5e7627e2608a2c83ac4d260e2ee12a348 100644 (file)
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -733,6 +733,7 @@ extern int xmkstemp_mode(char *template, int mode);
 extern int odb_mkstemp(char *template, size_t limit, const char *pattern);
 extern int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1);
 extern char *xgetcwd(void);
+extern FILE *fopen_for_writing(const char *path);
 
 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), (alloc) * sizeof(*(x)))
 

diff --git a/wrapper.c b/wrapper.c
index dae5675a960b636337dc7890fcfbcc559aa98567..371a7f0b63719f0a81ee64abb17b4ca6dbf9ba16 100644 (file)
--- a/wrapper.c
+++ b/wrapper.c
@@ -375,6 +375,19 @@ FILE *xfdopen(int fd, const char *mode)
        return stream;
 }
 
+FILE *fopen_for_writing(const char *path)
+{
+       FILE *ret = fopen(path, "w");
+
+       if (!ret && errno == EPERM) {
+               if (!unlink(path))
+                       ret = fopen(path, "w");
+               else
+                       errno = EPERM;
+       }
+       return ret;
+}
+
 int xmkstemp(char *template)
 {
        int fd;