patch-id: Add support for mbox format

I have an alias that takes two arguments and compares their patch IDs.
I would like to use to make sure I've tested exactly what I submit
(patch by patch), like

   git patch-cmp origin/master.. file-being-sent

However, I cannot do that because git patch-id is fooled by the "-- "
trailer that git format-patch puts, or likely by the MIME boundary.

This patch adds hunk parsing logic to git patch-id in order to detect an
out of place "-" line and split the patch when it comes.  In addition,
commit ids in the "From " lines are considered and printed in the output.

Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/patch-id.c b/builtin/patch-id.c
index 973d830ecfed016553088eae83b97c6c74201bfb..512530022edac398f8541ee6c400c7312659e730 100644 (file)
--- a/builtin/patch-id.c
+++ b/builtin/patch-id.c
@@ -28,10 +28,40 @@ static int remove_space(char *line)
        return dst - line;
 }
 
+static int scan_hunk_header(const char *p, int *p_before, int *p_after)
+{
+       static const char digits[] = "0123456789";
+       const char *q, *r;
+       int n;
+
+       q = p + 4;
+       n = strspn(q, digits);
+       if (q[n] == ',') {
+               q += n + 1;
+               n = strspn(q, digits);
+       }
+       if (n == 0 || q[n] != ' ' || q[n+1] != '+')
+               return 0;
+
+       r = q + n + 2;
+       n = strspn(r, digits);
+       if (r[n] == ',') {
+               r += n + 1;
+               n = strspn(r, digits);
+       }
+       if (n == 0)
+               return 0;
+
+       *p_before = atoi(q);
+       *p_after = atoi(r);
+       return 1;
+}
+
 int get_one_patchid(unsigned char *next_sha1, git_SHA_CTX *ctx)
 {
        static char line[1000];
        int patchlen = 0, found_next = 0;
+       int before = -1, after = -1;
 
        while (fgets(line, sizeof(line), stdin) != NULL) {
                char *p = line;
@@ -41,6 +71,8 @@ int get_one_patchid(unsigned char *next_sha1, git_SHA_CTX *ctx)
                        p += 10;
                else if (!memcmp(line, "commit ", 7))
                        p += 7;
+               else if (!memcmp(line, "From ", 5))
+                       p += 5;
 
                if (!get_sha1_hex(p, next_sha1)) {
                        found_next = 1;
@@ -51,13 +83,37 @@ int get_one_patchid(unsigned char *next_sha1, git_SHA_CTX *ctx)
                if (!patchlen && memcmp(line, "diff ", 5))
                        continue;
 
-               /* Ignore git-diff index header */
-               if (!memcmp(line, "index ", 6))
-                       continue;
+               /* Parsing diff header?  */
+               if (before == -1) {
+                       if (!memcmp(line, "index ", 6))
+                               continue;
+                       else if (!memcmp(line, "--- ", 4))
+                               before = after = 1;
+                       else if (!isalpha(line[0]))
+                               break;
+               }
 
-               /* Ignore line numbers when computing the SHA1 of the patch */
-               if (!memcmp(line, "@@ -", 4))
-                       continue;
+               /* Looking for a valid hunk header?  */
+               if (before == 0 && after == 0) {
+                       if (!memcmp(line, "@@ -", 4)) {
+                               /* Parse next hunk, but ignore line numbers.  */
+                               scan_hunk_header(line, &before, &after);
+                               continue;
+                       }
+
+                       /* Split at the end of the patch.  */
+                       if (memcmp(line, "diff ", 5))
+                               break;
+
+                       /* Else we're parsing another header.  */
+                       before = after = -1;
+               }
+
+               /* If we get here, we're inside a hunk.  */
+               if (line[0] == '-' || line[0] == ' ')
+                       before--;
+               if (line[0] == '+' || line[0] == ' ')
+                       after--;
 
                /* Compute the sha without whitespace */
                len = remove_space(line);

diff --git a/t/t4204-patch-id.sh b/t/t4204-patch-id.sh
index 04f7bae8503f7605f1403f55d0bf4d9cd146913d..68e2652814c6a52265407b0fdfb70162eb634d53 100755 (executable)
--- a/t/t4204-patch-id.sh
+++ b/t/t4204-patch-id.sh
@@ -18,6 +18,11 @@ test_expect_success 'patch-id output is well-formed' '
        grep "^[a-f0-9]\{40\} $(git rev-parse HEAD)$" output
 '
 
+calc_patch_id () {
+       git patch-id |
+               sed "s# .*##" > patch-id_"$1"
+}
+
 get_patch_id () {
        git log -p -1 "$1" | git patch-id |
                sed "s# .*##" > patch-id_"$1"
@@ -35,4 +40,27 @@ test_expect_success 'patch-id detects inequality' '
        ! test_cmp patch-id_master patch-id_notsame
 '
 
+test_expect_success 'patch-id supports git-format-patch output' '
+       get_patch_id master &&
+       git checkout same &&
+       git format-patch -1 --stdout | calc_patch_id same &&
+       test_cmp patch-id_master patch-id_same &&
+       set `git format-patch -1 --stdout | git patch-id` &&
+       test "$2" = `git rev-parse HEAD`
+'
+
+test_expect_success 'whitespace is irrelevant in footer' '
+       get_patch_id master &&
+       git checkout same &&
+       git format-patch -1 --stdout | sed "s/ \$//" | calc_patch_id same &&
+       test_cmp patch-id_master patch-id_same
+'
+
+test_expect_success 'patch-id supports git-format-patch MIME output' '
+       get_patch_id master &&
+       git checkout same &&
+       git format-patch -1 --attach --stdout | calc_patch_id same &&
+       test_cmp patch-id_master patch-id_same
+'
+
 test_done