remote-curl: refactor smart-http discovery
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index 15556c190d2e368fb2967a966263d1bcbfc09db2..e8c3e8081f9be0c4e9560a834b0f3df75ca81b72 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -291,7 +291,7 @@ static int parse_color_moved(const char *arg)
                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 }
 
-static int parse_color_moved_ws(const char *arg)
+static unsigned parse_color_moved_ws(const char *arg)
 {
        int ret = 0;
        struct string_list l = STRING_LIST_INIT_DUP;
@@ -304,7 +304,9 @@ static int parse_color_moved_ws(const char *arg)
                strbuf_addstr(&sb, i->string);
                strbuf_trim(&sb);
 
-               if (!strcmp(sb.buf, "ignore-space-change"))
+               if (!strcmp(sb.buf, "no"))
+                       ret = 0;
+               else if (!strcmp(sb.buf, "ignore-space-change"))
                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
@@ -312,15 +314,19 @@ static int parse_color_moved_ws(const char *arg)
                        ret |= XDF_IGNORE_WHITESPACE;
                else if (!strcmp(sb.buf, "allow-indentation-change"))
                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
-               else
-                       error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
+               else {
+                       ret |= COLOR_MOVED_WS_ERROR;
+                       error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
+               }
 
                strbuf_release(&sb);
        }
 
        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
-           (ret & XDF_WHITESPACE_FLAGS))
-               die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
+           (ret & XDF_WHITESPACE_FLAGS)) {
+               error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
+               ret |= COLOR_MOVED_WS_ERROR;
+       }
 
        string_list_clear(&l, 0);
 
@@ -341,8 +347,8 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                return 0;
        }
        if (!strcmp(var, "diff.colormovedws")) {
-               int cm = parse_color_moved_ws(value);
-               if (cm < 0)
+               unsigned cm = parse_color_moved_ws(value);
+               if (cm & COLOR_MOVED_WS_ERROR)
                        return -1;
                diff_color_moved_ws_default = cm;
                return 0;
@@ -489,7 +495,7 @@ static const char *external_diff(void)
 
        if (done_preparing)
                return external_diff_cmd;
-       external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
+       external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
        if (!external_diff_cmd)
                external_diff_cmd = external_diff_cmd_cfg;
        done_preparing = 1;
@@ -750,6 +756,8 @@ struct emitted_diff_symbol {
        const char *line;
        int len;
        int flags;
+       int indent_off;   /* Offset to first non-whitespace character */
+       int indent_width; /* The visual width of the indentation */
        enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -780,44 +788,85 @@ struct moved_entry {
        struct moved_entry *next_line;
 };
 
-/**
- * The struct ws_delta holds white space differences between moved lines, i.e.
- * between '+' and '-' lines that have been detected to be a move.
- * The string contains the difference in leading white spaces, before the
- * rest of the line is compared using the white space config for move
- * coloring. The current_longer indicates if the first string in the
- * comparision is longer than the second.
- */
-struct ws_delta {
-       char *string;
-       unsigned int current_longer : 1;
-};
-#define WS_DELTA_INIT { NULL, 0 }
-
 struct moved_block {
        struct moved_entry *match;
-       struct ws_delta wsd;
+       int wsd; /* The whitespace delta of this block */
 };
 
 static void moved_block_clear(struct moved_block *b)
 {
-       FREE_AND_NULL(b->wsd.string);
-       b->match = NULL;
+       memset(b, 0, sizeof(*b));
 }
 
-static int compute_ws_delta(const struct emitted_diff_symbol *a,
-                            const struct emitted_diff_symbol *b,
-                            struct ws_delta *out)
+#define INDENT_BLANKLINE INT_MIN
+
+static void fill_es_indent_data(struct emitted_diff_symbol *es)
 {
-       const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
-       const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
-       int d = longer->len - shorter->len;
+       unsigned int off = 0, i;
+       int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
+       const char *s = es->line;
+       const int len = es->len;
 
-       if (strncmp(longer->line + d, shorter->line, shorter->len))
+       /* skip any \v \f \r at start of indentation */
+       while (s[off] == '\f' || s[off] == '\v' ||
+              (s[off] == '\r' && off < len - 1))
+               off++;
+
+       /* calculate the visual width of indentation */
+       while(1) {
+               if (s[off] == ' ') {
+                       width++;
+                       off++;
+               } else if (s[off] == '\t') {
+                       width += tab_width - (width % tab_width);
+                       while (s[++off] == '\t')
+                               width += tab_width;
+               } else {
+                       break;
+               }
+       }
+
+       /* check if this line is blank */
+       for (i = off; i < len; i++)
+               if (!isspace(s[i]))
+                   break;
+
+       if (i == len) {
+               es->indent_width = INDENT_BLANKLINE;
+               es->indent_off = len;
+       } else {
+               es->indent_off = off;
+               es->indent_width = width;
+       }
+}
+
+static int compute_ws_delta(const struct emitted_diff_symbol *a,
+                           const struct emitted_diff_symbol *b,
+                           int *out)
+{
+       int a_len = a->len,
+           b_len = b->len,
+           a_off = a->indent_off,
+           a_width = a->indent_width,
+           b_off = b->indent_off,
+           b_width = b->indent_width;
+       int delta;
+
+       if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
+               *out = INDENT_BLANKLINE;
+               return 1;
+       }
+
+       if (a->s == DIFF_SYMBOL_PLUS)
+               delta = a_width - b_width;
+       else
+               delta = b_width - a_width;
+
+       if (a_len - a_off != b_len - b_off ||
+           memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
                return 0;
 
-       out->string = xmemdupz(longer->line, d);
-       out->current_longer = (a == longer);
+       *out = delta;
 
        return 1;
 }
@@ -829,51 +878,53 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
                                 int n)
 {
        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-       int al = cur->es->len, cl = l->len;
+       int al = cur->es->len, bl = match->es->len, cl = l->len;
        const char *a = cur->es->line,
                   *b = match->es->line,
                   *c = l->line;
-
-       int wslen;
+       int a_off = cur->es->indent_off,
+           a_width = cur->es->indent_width,
+           c_off = l->indent_off,
+           c_width = l->indent_width;
+       int delta;
 
        /*
-        * We need to check if 'cur' is equal to 'match'.
-        * As those are from the same (+/-) side, we do not need to adjust for
-        * indent changes. However these were found using fuzzy matching
-        * so we do have to check if they are equal.
+        * We need to check if 'cur' is equal to 'match'.  As those
+        * are from the same (+/-) side, we do not need to adjust for
+        * indent changes. However these were found using fuzzy
+        * matching so we do have to check if they are equal. Here we
+        * just check the lengths. We delay calling memcmp() to check
+        * the contents until later as if the length comparison for a
+        * and c fails we can avoid the call all together.
         */
-       if (strcmp(a, b))
+       if (al != bl)
                return 1;
 
-       if (!pmb->wsd.string)
-               /*
-                * The white space delta is not active? This can happen
-                * when we exit early in this function.
-                */
-               return 1;
+       /* If 'l' and 'cur' are both blank then they match. */
+       if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+               return 0;
 
        /*
-        * The indent changes of the block are known and stored in
-        * pmb->wsd; however we need to check if the indent changes of the
-        * current line are still the same as before.
-        *
-        * To do so we need to compare 'l' to 'cur', adjusting the
-        * one of them for the white spaces, depending which was longer.
+        * The indent changes of the block are known and stored in pmb->wsd;
+        * however we need to check if the indent changes of the current line
+        * match those of the current block and that the text of 'l' and 'cur'
+        * after the indentation match.
         */
+       if (cur->es->s == DIFF_SYMBOL_PLUS)
+               delta = a_width - c_width;
+       else
+               delta = c_width - a_width;
 
-       wslen = strlen(pmb->wsd.string);
-       if (pmb->wsd.current_longer) {
-               c += wslen;
-               cl -= wslen;
-       } else {
-               a += wslen;
-               al -= wslen;
-       }
-
-       if (al != cl || memcmp(a, c, al))
-               return 1;
+       /*
+        * If the previous lines of this block were all blank then set its
+        * whitespace delta.
+        */
+       if (pmb->wsd == INDENT_BLANKLINE)
+               pmb->wsd = delta;
 
-       return 0;
+       return !(delta == pmb->wsd && al - a_off == cl - c_off &&
+                !memcmp(a, b, al) && !
+                memcmp(a + a_off, c + c_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -939,6 +990,9 @@ static void add_lines_to_move_detection(struct diff_options *o,
                        continue;
                }
 
+               if (o->color_moved_ws_handling &
+                   COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+                       fill_es_indent_data(&o->emitted_symbols->buf[n]);
                key = prepare_entry(o, n);
                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
                        prev_line->next_line = key;
@@ -1017,8 +1071,7 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
 
                if (lp < pmb_nr && rp > -1 && lp < rp) {
                        pmb[lp] = pmb[rp];
-                       pmb[rp].match = NULL;
-                       pmb[rp].wsd.string = NULL;
+                       memset(&pmb[rp], 0, sizeof(pmb[rp]));
                        rp--;
                        lp++;
                }
@@ -1038,14 +1091,17 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
  * The last block consists of the (n - block_length)'th line up to but not
  * including the nth line.
  *
+ * Returns 0 if the last block is empty or is unset by this function, non zero
+ * otherwise.
+ *
  * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
  * Think of a way to unify them.
  */
-static void adjust_last_block(struct diff_options *o, int n, int block_length)
+static int adjust_last_block(struct diff_options *o, int n, int block_length)
 {
        int i, alnum_count = 0;
        if (o->color_moved == COLOR_MOVED_PLAIN)
-               return;
+               return block_length;
        for (i = 1; i < block_length + 1; i++) {
                const char *c = o->emitted_symbols->buf[n - i].line;
                for (; *c; c++) {
@@ -1053,11 +1109,12 @@ static void adjust_last_block(struct diff_options *o, int n, int block_length)
                                continue;
                        alnum_count++;
                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
-                               return;
+                               return 1;
                }
        }
        for (i = 1; i < block_length + 1; i++)
                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+       return 0;
 }
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
@@ -1067,7 +1124,7 @@ static void mark_color_as_moved(struct diff_options *o,
 {
        struct moved_block *pmb = NULL; /* potentially moved blocks */
        int pmb_nr = 0, pmb_alloc = 0;
-       int n, flipped_block = 1, block_length = 0;
+       int n, flipped_block = 0, block_length = 0;
 
 
        for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1075,6 +1132,7 @@ static void mark_color_as_moved(struct diff_options *o,
                struct moved_entry *key;
                struct moved_entry *match = NULL;
                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+               enum diff_symbol last_symbol = 0;
 
                switch (l->s) {
                case DIFF_SYMBOL_PLUS:
@@ -1090,7 +1148,7 @@ static void mark_color_as_moved(struct diff_options *o,
                        free(key);
                        break;
                default:
-                       flipped_block = 1;
+                       flipped_block = 0;
                }
 
                if (!match) {
@@ -1101,13 +1159,16 @@ static void mark_color_as_moved(struct diff_options *o,
                                moved_block_clear(&pmb[i]);
                        pmb_nr = 0;
                        block_length = 0;
+                       flipped_block = 0;
+                       last_symbol = l->s;
                        continue;
                }
 
-               l->flags |= DIFF_SYMBOL_MOVED_LINE;
-
-               if (o->color_moved == COLOR_MOVED_PLAIN)
+               if (o->color_moved == COLOR_MOVED_PLAIN) {
+                       last_symbol = l->s;
+                       l->flags |= DIFF_SYMBOL_MOVED_LINE;
                        continue;
+               }
 
                if (o->color_moved_ws_handling &
                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -1130,21 +1191,27 @@ static void mark_color_as_moved(struct diff_options *o,
                                                             &pmb[pmb_nr].wsd))
                                                pmb[pmb_nr++].match = match;
                                } else {
-                                       pmb[pmb_nr].wsd.string = NULL;
+                                       pmb[pmb_nr].wsd = 0;
                                        pmb[pmb_nr++].match = match;
                                }
                        }
 
-                       flipped_block = (flipped_block + 1) % 2;
+                       if (adjust_last_block(o, n, block_length) &&
+                           pmb_nr && last_symbol != l->s)
+                               flipped_block = (flipped_block + 1) % 2;
+                       else
+                               flipped_block = 0;
 
-                       adjust_last_block(o, n, block_length);
                        block_length = 0;
                }
 
-               block_length++;
-
-               if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
-                       l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+               if (pmb_nr) {
+                       block_length++;
+                       l->flags |= DIFF_SYMBOL_MOVED_LINE;
+                       if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
+                               l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+               }
+               last_symbol = l->s;
        }
        adjust_last_block(o, n, block_length);
 
@@ -1488,7 +1555,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
                             const char *line, int len, unsigned flags)
 {
-       struct emitted_diff_symbol e = {line, len, flags, s};
+       struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
 
        if (o->emitted_symbols)
                append_emitted_diff_symbol(o, &e);
@@ -1637,7 +1704,8 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
        strbuf_release(&msgbuf);
 }
 
-static struct diff_tempfile *claim_diff_tempfile(void) {
+static struct diff_tempfile *claim_diff_tempfile(void)
+{
        int i;
        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
                if (!diff_temp[i].name)
@@ -3476,7 +3544,7 @@ static void builtin_diff(const char *name_a,
                o->found_changes = 1;
        } else {
                /* Crazy xdl interfaces.. */
-               const char *diffopts = getenv("GIT_DIFF_OPTS");
+               const char *diffopts;
                const char *v;
                xpparam_t xpp;
                xdemitconf_t xecfg;
@@ -3519,12 +3587,15 @@ static void builtin_diff(const char *name_a,
                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
                if (pe)
                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
+
+               diffopts = getenv("GIT_DIFF_OPTS");
                if (!diffopts)
                        ;
                else if (skip_prefix(diffopts, "--unified=", &v))
                        xecfg.ctxlen = strtoul(v, NULL, 10);
                else if (skip_prefix(diffopts, "-u", &v))
                        xecfg.ctxlen = strtoul(v, NULL, 10);
+
                if (o->word_diff)
                        init_diff_words_data(&ecbdata, o, one, two);
                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
@@ -4819,7 +4890,8 @@ static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
        return 0;
 }
 
-static void enable_patch_output(int *fmt) {
+static void enable_patch_output(int *fmt)
+{
        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
        *fmt |= DIFF_FORMAT_PATCH;
 }
@@ -5034,10 +5106,15 @@ int diff_opt_parse(struct diff_options *options,
        else if (skip_prefix(arg, "--color-moved=", &arg)) {
                int cm = parse_color_moved(arg);
                if (cm < 0)
-                       die("bad --color-moved argument: %s", arg);
+                       return error("bad --color-moved argument: %s", arg);
                options->color_moved = cm;
+       } else if (!strcmp(arg, "--no-color-moved-ws")) {
+               options->color_moved_ws_handling = 0;
        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
-               options->color_moved_ws_handling = parse_color_moved_ws(arg);
+               unsigned cm = parse_color_moved_ws(arg);
+               if (cm & COLOR_MOVED_WS_ERROR)
+                       return -1;
+               options->color_moved_ws_handling = cm;
        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
                options->use_color = 1;
                options->word_diff = DIFF_WORDS_COLOR;