decorate: color each token separately

Wrap "tag:" prefixes and the arrows in "HEAD -> branch" decorations in
their own color sequences. Otherwise, if --graph is used, tag names or
arrows can end up uncolored when %w width formatting breaks a line just
before them. This is because --graph resets the color after doing its
drawing at the start of a line.

Amend test t4207-log-decoration-colors.sh accordingly.

Signed-off-by: Andy Koppe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: ak2

log-tree.c

@@ -342,26 +342,34 @@ void format_decorations(struct strbuf *sb,
 		 * appeared, skipping the entry for current.
 		 */
 		if (decoration != current_and_HEAD) {
+			const char *color =
+				decorate_get_color(use_color, decoration->type);
+
 			if (*prefix) {
 				strbuf_addstr(sb, color_commit);
 				strbuf_addstr(sb, prefix);
 				strbuf_addstr(sb, color_reset);
 			}
 
-			strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
-			if (decoration->type == DECORATION_REF_TAG)
+			if (decoration->type == DECORATION_REF_TAG) {
+				strbuf_addstr(sb, color);
 				strbuf_addstr(sb, "tag: ");
+				strbuf_addstr(sb, color_reset);
+			}
 
+			strbuf_addstr(sb, color);
 			show_name(sb, decoration);
+			strbuf_addstr(sb, color_reset);
 
 			if (current_and_HEAD &&
 			    decoration->type == DECORATION_REF_HEAD) {
+				strbuf_addstr(sb, color);
 				strbuf_addstr(sb, " -> ");
 				strbuf_addstr(sb, color_reset);
 				strbuf_addstr(sb, decorate_get_color(use_color, current_and_HEAD->type));
 				show_name(sb, current_and_HEAD);
+				strbuf_addstr(sb, color_reset);
 			}
-			strbuf_addstr(sb, color_reset);
 
 			prefix = separator;
 		}

t/t4207-log-decoration-colors.sh

@@ -53,15 +53,17 @@ cmp_filtered_decorations () {
 # to this test since it does not contain any decoration, hence --first-parent
 test_expect_success 'commit decorations colored correctly' '
 	cat >expect <<-EOF &&
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_HEAD}HEAD -> \
-${c_reset}${c_branch}main${c_reset}${c_commit}, \
-${c_reset}${c_tag}tag: v1.0${c_reset}${c_commit}, \
-${c_reset}${c_tag}tag: B${c_reset}${c_commit})${c_reset} B
-${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_tag}tag: A1${c_reset}${c_commit}, \
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_HEAD}HEAD${c_reset}\
+${c_HEAD} -> ${c_reset}${c_branch}main${c_reset}${c_commit}, \
+${c_reset}${c_tag}tag: ${c_reset}${c_tag}v1.0${c_reset}${c_commit}, \
+${c_reset}${c_tag}tag: ${c_reset}${c_tag}B${c_reset}${c_commit})${c_reset} B
+${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_tag}tag: ${c_reset}${c_tag}A1${c_reset}${c_commit}, \
 ${c_reset}${c_remoteBranch}other/main${c_reset}${c_commit})${c_reset} A1
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_stash}refs/stash${c_reset}${c_commit})${c_reset} \
-On main: Changes to A.t
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_tag}tag: A${c_reset}${c_commit})${c_reset} A
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_stash}refs/stash${c_reset}${c_commit})${c_reset} On main: Changes to A.t
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_tag}tag: ${c_reset}${c_tag}A${c_reset}${c_commit})${c_reset} A
 	EOF
 
 	git log --first-parent --no-abbrev --decorate --oneline --color=always --all >actual &&
@@ -76,12 +78,14 @@ test_expect_success 'test coloring with replace-objects' '
 	git replace HEAD~1 HEAD~2 &&
 
 	cat >expect <<-EOF &&
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_HEAD}HEAD -> \
-${c_reset}${c_branch}main${c_reset}${c_commit}, \
-${c_reset}${c_tag}tag: D${c_reset}${c_commit})${c_reset} D
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_tag}tag: C${c_reset}${c_commit}, \
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_HEAD}HEAD${c_reset}\
+${c_HEAD} -> ${c_reset}${c_branch}main${c_reset}${c_commit}, \
+${c_reset}${c_tag}tag: ${c_reset}${c_tag}D${c_reset}${c_commit})${c_reset} D
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_tag}tag: ${c_reset}${c_tag}C${c_reset}${c_commit}, \
 ${c_reset}${c_grafted}replaced${c_reset}${c_commit})${c_reset} B
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_tag}tag: A${c_reset}${c_commit})${c_reset} A
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_tag}tag: ${c_reset}${c_tag}A${c_reset}${c_commit})${c_reset} A
 EOF
 
 	git log --first-parent --no-abbrev --decorate --oneline --color=always HEAD >actual &&
@@ -100,13 +104,15 @@ test_expect_success 'test coloring with grafted commit' '
 	git replace --graft HEAD HEAD~2 &&
 
 	cat >expect <<-EOF &&
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_HEAD}HEAD -> \
-${c_reset}${c_branch}main${c_reset}${c_commit}, \
-${c_reset}${c_tag}tag: D${c_reset}${c_commit}, \
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_HEAD}HEAD${c_reset}\
+${c_HEAD} -> ${c_reset}${c_branch}main${c_reset}${c_commit}, \
+${c_reset}${c_tag}tag: ${c_reset}${c_tag}D${c_reset}${c_commit}, \
 ${c_reset}${c_grafted}replaced${c_reset}${c_commit})${c_reset} D
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_tag}tag: v1.0${c_reset}${c_commit}, \
-${c_reset}${c_tag}tag: B${c_reset}${c_commit})${c_reset} B
-	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}${c_tag}tag: A${c_reset}${c_commit})${c_reset} A
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_tag}tag: ${c_reset}${c_tag}v1.0${c_reset}${c_commit}, \
+${c_reset}${c_tag}tag: ${c_reset}${c_tag}B${c_reset}${c_commit})${c_reset} B
+	${c_commit}COMMIT_ID${c_reset}${c_commit} (${c_reset}\
+${c_tag}tag: ${c_reset}${c_tag}A${c_reset}${c_commit})${c_reset} A
 	EOF
 
 	git log --first-parent --no-abbrev --decorate --oneline --color=always HEAD >actual &&