commit-tree: encourage UTF-8 commit messages.

Introduce is_utf() to check if a text looks like it is encoded
in UTF-8, utf8_width() to count display width, and implements
print_wrapped_text() using them.

git-commit-tree warns if the commit message does not minimally
conform to the UTF-8 encoding when i18n.commitencoding is either
unset, or set to "utf-8".

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

diff --git a/Makefile b/Makefile
index ebc1a17e701beb5edbb03bc94cad368424e6bc7b..d56970c569985c956d2ba6a373ac4b90e9cdd636 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -230,7 +230,8 @@ LIB_H = \
        archive.h blob.h cache.h commit.h csum-file.h delta.h grep.h \
        diff.h object.h pack.h pkt-line.h quote.h refs.h list-objects.h sideband.h \
        run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
-       tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h
+       tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h \
+       utf8.h
 
 DIFF_OBJS = \
        diff.o diff-lib.o diffcore-break.o diffcore-order.o \
@@ -249,7 +250,8 @@ LIB_OBJS = \
        revision.o pager.o tree-walk.o xdiff-interface.o \
        write_or_die.o trace.o list-objects.o grep.o \
        alloc.o merge-file.o path-list.o help.o unpack-trees.o $(DIFF_OBJS) \
-       color.o wt-status.o archive-zip.o archive-tar.o
+       color.o wt-status.o archive-zip.o archive-tar.o \
+       utf8.o
 
 BUILTIN_OBJS = \
        builtin-add.o \

diff --git a/builtin-commit-tree.c b/builtin-commit-tree.c
index bc28770664aac2c51bdd83125f36e2b15903535c..f641787988e197209f097cbc9d1b260a2cb6d9d8 100644 (file)
--- a/builtin-commit-tree.c
+++ b/builtin-commit-tree.c
@@ -7,6 +7,7 @@
 #include "commit.h"
 #include "tree.h"
 #include "builtin.h"
+#include "utf8.h"
 
 #define BLOCKING (1ul << 14)
 
@@ -32,7 +33,7 @@ static void add_buffer(char **bufp, unsigned int *sizep, const char *fmt, ...)
        len = vsnprintf(one_line, sizeof(one_line), fmt, args);
        va_end(args);
        size = *sizep;
-       newsize = size + len;
+       newsize = size + len + 1;
        alloc = (size + 32767) & ~32767;
        buf = *bufp;
        if (newsize > alloc) {
@@ -40,7 +41,7 @@ static void add_buffer(char **bufp, unsigned int *sizep, const char *fmt, ...)
                buf = xrealloc(buf, alloc);
                *bufp = buf;
        }
-       *sizep = newsize;
+       *sizep = newsize - 1;
        memcpy(buf + size, one_line, len);
 }
 
@@ -77,6 +78,11 @@ static int new_parent(int idx)
        return 1;
 }
 
+static const char commit_utf8_warn[] =
+"Warning: commit message does not conform to UTF-8.\n"
+"You may want to amend it after fixing the message, or set the config\n"
+"variable i18n.commitencoding to the encoding your project uses.\n";
+
 int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 {
        int i;
@@ -130,6 +136,11 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
        while (fgets(comment, sizeof(comment), stdin) != NULL)
                add_buffer(&buffer, &size, "%s", comment);
 
+       /* And check the encoding */
+       buffer[size] = '\0';
+       if (!strcmp(git_commit_encoding, "utf-8") && !is_utf8(buffer))
+               fprintf(stderr, commit_utf8_warn);
+
        if (!write_sha1_file(buffer, size, commit_type, commit_sha1)) {
                printf("%s\n", sha1_to_hex(commit_sha1));
                return 0;

diff --git a/utf8.c b/utf8.c
new file mode 100644 (file)
index 0000000..8fa6257
--- /dev/null
+++ b/utf8.c
@@ -0,0 +1,278 @@
+#include "git-compat-util.h"
+#include "utf8.h"
+
+/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
+
+struct interval {
+  int first;
+  int last;
+};
+
+/* auxiliary function for binary search in interval table */
+static int bisearch(wchar_t ucs, const struct interval *table, int max) {
+       int min = 0;
+       int mid;
+
+       if (ucs < table[0].first || ucs > table[max].last)
+               return 0;
+       while (max >= min) {
+               mid = (min + max) / 2;
+               if (ucs > table[mid].last)
+                       min = mid + 1;
+               else if (ucs < table[mid].first)
+                       max = mid - 1;
+               else
+                       return 1;
+       }
+
+       return 0;
+}
+
+/* The following two functions define the column width of an ISO 10646
+ * character as follows:
+ *
+ *    - The null character (U+0000) has a column width of 0.
+ *
+ *    - Other C0/C1 control characters and DEL will lead to a return
+ *      value of -1.
+ *
+ *    - Non-spacing and enclosing combining characters (general
+ *      category code Mn or Me in the Unicode database) have a
+ *      column width of 0.
+ *
+ *    - SOFT HYPHEN (U+00AD) has a column width of 1.
+ *
+ *    - Other format characters (general category code Cf in the Unicode
+ *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
+ *
+ *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
+ *      have a column width of 0.
+ *
+ *    - Spacing characters in the East Asian Wide (W) or East Asian
+ *      Full-width (F) category as defined in Unicode Technical
+ *      Report #11 have a column width of 2.
+ *
+ *    - All remaining characters (including all printable
+ *      ISO 8859-1 and WGL4 characters, Unicode control characters,
+ *      etc.) have a column width of 1.
+ *
+ * This implementation assumes that wchar_t characters are encoded
+ * in ISO 10646.
+ */
+
+static int wcwidth(wchar_t ch)
+{
+       /*
+        * Sorted list of non-overlapping intervals of non-spacing characters,
+        * generated by
+        *   "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
+        */
+       static const struct interval combining[] = {
+               { 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
+               { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
+               { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
+               { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
+               { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
+               { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
+               { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
+               { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
+               { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
+               { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
+               { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
+               { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
+               { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
+               { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
+               { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
+               { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
+               { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
+               { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
+               { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
+               { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
+               { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
+               { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
+               { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
+               { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
+               { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
+               { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
+               { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
+               { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
+               { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
+               { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
+               { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
+               { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
+               { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
+               { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
+               { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
+               { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
+               { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
+               { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
+               { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
+               { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
+               { 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
+               { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
+       };
+
+       /* test for 8-bit control characters */
+       if (ch == 0)
+               return 0;
+       if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
+               return -1;
+
+       /* binary search in table of non-spacing characters */
+       if (bisearch(ch, combining, sizeof(combining)
+                               / sizeof(struct interval) - 1))
+               return 0;
+
+       /*
+        * If we arrive here, ch is neither a combining nor a C0/C1
+        * control character.
+        */
+
+       return 1 +
+               (ch >= 0x1100 &&
+                    /* Hangul Jamo init. consonants */
+                (ch <= 0x115f ||
+                 ch == 0x2329 || ch == 0x232a ||
+                  /* CJK ... Yi */
+                 (ch >= 0x2e80 && ch <= 0xa4cf &&
+                  ch != 0x303f) ||
+                 /* Hangul Syllables */
+                 (ch >= 0xac00 && ch <= 0xd7a3) ||
+                 /* CJK Compatibility Ideographs */
+                 (ch >= 0xf900 && ch <= 0xfaff) ||
+                 /* CJK Compatibility Forms */
+                 (ch >= 0xfe30 && ch <= 0xfe6f) ||
+                 /* Fullwidth Forms */
+                 (ch >= 0xff00 && ch <= 0xff60) ||
+                 (ch >= 0xffe0 && ch <= 0xffe6) ||
+                 (ch >= 0x20000 && ch <= 0x2fffd) ||
+                 (ch >= 0x30000 && ch <= 0x3fffd)));
+}
+
+/*
+ * This function returns the number of columns occupied by the character
+ * pointed to by the variable start. The pointer is updated to point at
+ * the next character. If it was not valid UTF-8, the pointer is set to NULL.
+ */
+int utf8_width(const char **start)
+{
+       unsigned char *s = (unsigned char *)*start;
+       wchar_t ch;
+
+       if (*s < 0x80) {
+               /* 0xxxxxxx */
+               ch = *s;
+               *start += 1;
+       } else if ((s[0] & 0xe0) == 0xc0) {
+               /* 110XXXXx 10xxxxxx */
+               if ((s[1] & 0xc0) != 0x80 ||
+                               /* overlong? */
+                               (s[0] & 0xfe) == 0xc0)
+                       goto invalid;
+               ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
+               *start += 2;
+       } else if ((s[0] & 0xf0) == 0xe0) {
+               /* 1110XXXX 10Xxxxxx 10xxxxxx */
+               if ((s[1] & 0xc0) != 0x80 ||
+                               (s[2] & 0xc0) != 0x80 ||
+                               /* overlong? */
+                               (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
+                               /* surrogate? */
+                               (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
+                               /* U+FFFE or U+FFFF? */
+                               (s[0] == 0xef && s[1] == 0xbf &&
+                                (s[2] & 0xfe) == 0xbe))
+                       goto invalid;
+               ch = ((s[0] & 0x0f) << 12) |
+                       ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
+               *start += 3;
+       } else if ((s[0] & 0xf8) == 0xf0) {
+               /* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
+               if ((s[1] & 0xc0) != 0x80 ||
+                               (s[2] & 0xc0) != 0x80 ||
+                               (s[3] & 0xc0) != 0x80 ||
+                               /* overlong? */
+                               (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
+                               /* > U+10FFFF? */
+                               (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
+                       goto invalid;
+               ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
+                       ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
+               *start += 4;
+       } else {
+invalid:
+               *start = NULL;
+               return 0;
+       }
+
+       return wcwidth(ch);
+}
+
+int is_utf8(const char *text)
+{
+       while (*text) {
+               if (*text == '\n' || *text == '\t' || *text == '\r') {
+                       text++;
+                       continue;
+               }
+               utf8_width(&text);
+               if (!text)
+                       return 0;
+       }
+       return 1;
+}
+
+static void print_spaces(int count)
+{
+       static const char s[] = "                    ";
+       while (count >= sizeof(s)) {
+               fwrite(s, sizeof(s) - 1, 1, stdout);
+               count -= sizeof(s) - 1;
+       }
+       fwrite(s, count, 1, stdout);
+}
+
+/*
+ * Wrap the text, if necessary. The variable indent is the indent for the
+ * first line, indent2 is the indent for all other lines.
+ */
+void print_wrapped_text(const char *text, int indent, int indent2, int width)
+{
+       int w = indent, assume_utf8 = is_utf8(text);
+       const char *bol = text, *space = NULL;
+
+       for (;;) {
+               char c = *text;
+               if (!c || isspace(c)) {
+                       if (w < width || !space) {
+                               const char *start = bol;
+                               if (space)
+                                       start = space;
+                               else
+                                       print_spaces(indent);
+                               fwrite(start, text - start, 1, stdout);
+                               if (!c) {
+                                       putchar('\n');
+                                       return;
+                               } else if (c == '\t')
+                                       w |= 0x07;
+                               space = text;
+                               w++;
+                               text++;
+                       }
+                       else {
+                               putchar('\n');
+                               text = bol = space + 1;
+                               space = NULL;
+                               w = indent = indent2;
+                       }
+                       continue;
+               }
+               if (assume_utf8)
+                       w += utf8_width(&text);
+               else {
+                       w++;
+                       text++;
+               }
+       }
+}

diff --git a/utf8.h b/utf8.h
new file mode 100644 (file)
index 0000000..a0d7f59
--- /dev/null
+++ b/utf8.h
@@ -0,0 +1,8 @@
+#ifndef GIT_UTF8_H
+#define GIT_UTF8_H
+
+int utf8_width(const char **start);
+int is_utf8(const char *text);
+void print_wrapped_text(const char *text, int indent, int indent2, int len);
+
+#endif