git am: Display some help text when patch is empty

diff --git a/ws.c b/ws.c
index c0893386e6c8aa3af002e847d228dfc5ef64a9cf..d7b8c33f14195ba7ebe86bdbca2fea8f1b22ad37 100644 (file)
--- a/ws.c
+++ b/ws.c
@@ -10,7 +10,8 @@
 static struct whitespace_rule {
        const char *rule_name;
        unsigned rule_bits;
-       unsigned loosens_error;
+       unsigned loosens_error:1,
+               exclude_default:1;
 } whitespace_rule_names[] = {
        { "trailing-space", WS_TRAILING_SPACE, 0 },
        { "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
@@ -18,6 +19,7 @@ static struct whitespace_rule {
        { "cr-at-eol", WS_CR_AT_EOL, 1 },
        { "blank-at-eol", WS_BLANK_AT_EOL, 0 },
        { "blank-at-eof", WS_BLANK_AT_EOF, 0 },
+       { "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
 };
 
 unsigned parse_whitespace_rule(const char *string)
@@ -56,6 +58,9 @@ unsigned parse_whitespace_rule(const char *string)
                }
                string = ep;
        }
+
+       if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
+               die("cannot enforce both tab-in-indent and indent-with-non-tab");
        return rule;
 }
 
@@ -82,7 +87,8 @@ unsigned whitespace_rule(const char *pathname)
                        unsigned all_rule = 0;
                        int i;
                        for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
-                               if (!whitespace_rule_names[i].loosens_error)
+                               if (!whitespace_rule_names[i].loosens_error &&
+                                   !whitespace_rule_names[i].exclude_default)
                                        all_rule |= whitespace_rule_names[i].rule_bits;
                        return all_rule;
                } else if (ATTR_FALSE(value)) {
@@ -125,6 +131,11 @@ char *whitespace_error_string(unsigned ws)
                        strbuf_addstr(&err, ", ");
                strbuf_addstr(&err, "indent with spaces");
        }
+       if (ws & WS_TAB_IN_INDENT) {
+               if (err.len)
+                       strbuf_addstr(&err, ", ");
+               strbuf_addstr(&err, "tab in indent");
+       }
        return strbuf_detach(&err, NULL);
 }
 
@@ -163,7 +174,7 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
                }
        }
 
-       /* Check for space before tab in initial indent. */
+       /* Check indentation */
        for (i = 0; i < len; i++) {
                if (line[i] == ' ')
                        continue;
@@ -175,11 +186,19 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
                                fputs(ws, stream);
                                fwrite(line + written, i - written, 1, stream);
                                fputs(reset, stream);
+                               fwrite(line + i, 1, 1, stream);
                        }
-               } else if (stream)
-                       fwrite(line + written, i - written, 1, stream);
-               if (stream)
-                       fwrite(line + i, 1, 1, stream);
+               } else if (ws_rule & WS_TAB_IN_INDENT) {
+                       result |= WS_TAB_IN_INDENT;
+                       if (stream) {
+                               fwrite(line + written, i - written, 1, stream);
+                               fputs(ws, stream);
+                               fwrite(line + i, 1, 1, stream);
+                               fputs(reset, stream);
+                       }
+               } else if (stream) {
+                       fwrite(line + written, i - written + 1, 1, stream);
+               }
                written = i + 1;
        }
 
@@ -252,8 +271,8 @@ int ws_blank_line(const char *line, int len, unsigned ws_rule)
        return 1;
 }
 
-/* Copy the line to the buffer while fixing whitespaces */
-int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *error_count)
+/* Copy the line onto the end of the strbuf while fixing whitespaces */
+void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
 {
        /*
         * len is number of bytes to be copied from src, starting
@@ -267,7 +286,6 @@ int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *erro
        int last_tab_in_indent = -1;
        int last_space_in_indent = -1;
        int need_fix_leading_space = 0;
-       char *buf;
 
        /*
         * Strip trailing whitespace
@@ -307,7 +325,6 @@ int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *erro
                        break;
        }
 
-       buf = dst;
        if (need_fix_leading_space) {
                /* Process indent ourselves */
                int consecutive_spaces = 0;
@@ -329,28 +346,41 @@ int ws_fix_copy(char *dst, const char *src, int len, unsigned ws_rule, int *erro
                        char ch = src[i];
                        if (ch != ' ') {
                                consecutive_spaces = 0;
-                               *dst++ = ch;
+                               strbuf_addch(dst, ch);
                        } else {
                                consecutive_spaces++;
                                if (consecutive_spaces == 8) {
-                                       *dst++ = '\t';
+                                       strbuf_addch(dst, '\t');
                                        consecutive_spaces = 0;
                                }
                        }
                }
                while (0 < consecutive_spaces--)
-                       *dst++ = ' ';
+                       strbuf_addch(dst, ' ');
+               len -= last;
+               src += last;
+               fixed = 1;
+       } else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
+               /* Expand tabs into spaces */
+               int last = last_tab_in_indent + 1;
+               for (i = 0; i < last; i++) {
+                       if (src[i] == '\t')
+                               do {
+                                       strbuf_addch(dst, ' ');
+                               } while (dst->len % 8);
+                       else
+                               strbuf_addch(dst, src[i]);
+               }
                len -= last;
                src += last;
                fixed = 1;
        }
 
-       memcpy(dst, src, len);
+       strbuf_add(dst, src, len);
        if (add_cr_to_tail)
-               dst[len++] = '\r';
+               strbuf_addch(dst, '\r');
        if (add_nl_to_tail)
-               dst[len++] = '\n';
+               strbuf_addch(dst, '\n');
        if (fixed && error_count)
                (*error_count)++;
-       return dst + len - buf;
 }