perf hists: Do column alignment on the format iterator

index a5a5390476ac..af608d5da17d 100644
@@ -1086,16 +1086,17 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 			.folded_sign	= folded_sign,
 			.current_entry	= current_entry,
 		};
-		struct perf_hpp hpp = {
-			.buf		= s,
-			.size		= sizeof(s),
-			.ptr		= &arg,
-		};
 		int column = 0;
 
 		hist_browser__gotorc(browser, row, 0);
 
 		hists__for_each_format(browser->hists, fmt) {
+			struct perf_hpp hpp = {
+				.buf	= s,
+				.size	= sizeof(s),
+				.ptr	= &arg,
+			};
+
 			if (perf_hpp__should_skip(fmt, entry->hists) ||
 			    column++ < browser->b.horiz_scroll)
 				continue;

@@ -1122,8 +1123,9 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 			if (fmt->color) {
 				width -= fmt->color(fmt, &hpp, entry);
 			} else {
-				width -= fmt->entry(fmt, &hpp, entry);
+				hist_entry__snprintf_alignment(entry, &hpp, fmt, fmt->entry(fmt, &hpp, entry));
 				ui_browser__printf(&browser->b, "%s", s);
+				width -= hpp.buf - s;
 			}
 		}
 

@@ -1452,9 +1454,10 @@ static int hist_browser__fprintf_entry(struct hist_browser *browser,
 			first = false;
 
 		ret = fmt->entry(fmt, &hpp, he);
+		ret = hist_entry__snprintf_alignment(he, &hpp, fmt, ret);
 		advance_hpp(&hpp, ret);
 	}
-	printed += fprintf(fp, "%s\n", rtrim(s));
+	printed += fprintf(fp, "%s\n", s);
 
 	if (folded_sign == '-')
 		printed += hist_browser__fprintf_callchain(browser, he, fp);

index 1a6e8f7f38c4..87b022ff03d8 100644
@@ -403,6 +403,7 @@ static int hist_entry__snprintf(struct hist_entry *he, struct perf_hpp *hpp)
 		else
 			ret = fmt->entry(fmt, hpp, he);
 
+		ret = hist_entry__snprintf_alignment(he, hpp, fmt, ret);
 		advance_hpp(hpp, ret);
 	}
 

index 12f2d794dc28..561e9473a915 100644
@@ -1015,6 +1015,27 @@ void hist_entry__delete(struct hist_entry *he)
 }
 
 /*
+ * If this is not the last column, then we need to pad it according to the
+ * pre-calculated max lenght for this column, otherwise don't bother adding
+ * spaces because that would break viewing this with, for instance, 'less',
+ * that would show tons of trailing spaces when a long C++ demangled method
+ * names is sampled.
+*/
+int hist_entry__snprintf_alignment(struct hist_entry *he, struct perf_hpp *hpp,
+				   struct perf_hpp_fmt *fmt, int printed)
+{
+	if (!list_is_last(&fmt->list, &he->hists->hpp_list->fields)) {
+		const int width = fmt->width(fmt, hpp, hists_to_evsel(he->hists));
+		if (printed < width) {
+			advance_hpp(hpp, printed);
+			printed = scnprintf(hpp->buf, hpp->size, "%-*s", width - printed, " ");
+		}
+	}
+
+	return printed;
+}
+
+/*
  * collapse the histogram
  */
 

index 1c7544a8fe1a..840b6d6aa44f 100644
@@ -122,11 +122,16 @@ struct hist_entry *__hists__add_entry(struct hists *hists,
 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
 			 int max_stack_depth, void *arg);
 
+struct perf_hpp;
+struct perf_hpp_fmt;
+
 int64_t hist_entry__cmp(struct hist_entry *left, struct hist_entry *right);
 int64_t hist_entry__collapse(struct hist_entry *left, struct hist_entry *right);
 int hist_entry__transaction_len(void);
 int hist_entry__sort_snprintf(struct hist_entry *he, char *bf, size_t size,
 			      struct hists *hists);
+int hist_entry__snprintf_alignment(struct hist_entry *he, struct perf_hpp *hpp,
+				   struct perf_hpp_fmt *fmt, int printed);
 void hist_entry__delete(struct hist_entry *he);
 
 void perf_evsel__output_resort(struct perf_evsel *evsel, struct ui_progress *prog);

index de620f7f40f4..c0ddde280584 100644
@@ -247,10 +247,8 @@ static int _hist_entry__sym_snprintf(struct map *map, struct symbol *sym,
 			ret += repsep_snprintf(bf + ret, size - ret, "%s", sym->name);
 			ret += repsep_snprintf(bf + ret, size - ret, "+0x%llx",
 					ip - map->unmap_ip(map, sym->start));
-			ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
-				       width - ret, "");
 		} else {
-			ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
+			ret += repsep_snprintf(bf + ret, size - ret, "%.*s",
 					       width - ret,
 					       sym->name);
 		}

@@ -258,14 +256,9 @@ static int _hist_entry__sym_snprintf(struct map *map, struct symbol *sym,
 		size_t len = BITS_PER_LONG / 4;
 		ret += repsep_snprintf(bf + ret, size - ret, "%-#.*llx",
 				       len, ip);
-		ret += repsep_snprintf(bf + ret, size - ret, "%-*s",
-				       width - ret, "");
 	}
 
-	if (ret > width)
-		bf[width] = '\0';
-
-	return width;
+	return ret;
 }
 
 static int hist_entry__sym_snprintf(struct hist_entry *he, char *bf,

@@ -811,7 +804,7 @@ static int hist_entry__locked_snprintf(struct hist_entry *he, char *bf,
 	else
 		out = "No";
 
-	return repsep_snprintf(bf, size, "%-*s", width, out);
+	return repsep_snprintf(bf, size, "%.*s", width, out);
 }
 
 static int64_t

index af608d5da17d..1819771243f9 100644
@@ -1061,7 +1061,6 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 				    struct hist_entry *entry,
 				    unsigned short row)
 {
-	char s[256];
 	int printed = 0;
 	int width = browser->b.width;
 	char folded_sign = ' ';

@@ -1091,6 +1090,7 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 		hist_browser__gotorc(browser, row, 0);
 
 		hists__for_each_format(browser->hists, fmt) {
+			char s[2048];
 			struct perf_hpp hpp = {
 				.buf	= s,
 				.size	= sizeof(s),

@@ -1121,12 +1121,18 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 			}
 
 			if (fmt->color) {
-				width -= fmt->color(fmt, &hpp, entry);
+				int ret = fmt->color(fmt, &hpp, entry);
+				hist_entry__snprintf_alignment(entry, &hpp, fmt, ret);
+				/*
+				 * fmt->color() already used ui_browser to
+				 * print the non alignment bits, skip it (+ret):
+				 */
+				ui_browser__printf(&browser->b, "%s", s + ret);
 			} else {
 				hist_entry__snprintf_alignment(entry, &hpp, fmt, fmt->entry(fmt, &hpp, entry));
 				ui_browser__printf(&browser->b, "%s", s);
-				width -= hpp.buf - s;
 			}
+			width -= hpp.buf - s;
 		}
 
 		/* The scroll bar isn't being used */