fix an out-of-bounds error in the new stream-based report code when centering very short headlines, refactor indentation code, add tests.

src/report.c

@@ -120,7 +120,14 @@ void newline(stream *out) {
     sputs("", out);
 }
 
-static const char *spaces = "                                ";
+void write_spaces(stream *out, size_t num) {
+    static const char spaces[REPORTWIDTH] = "                                                                             ";
+    while (num > 0) {
+        size_t bytes = (num > REPORTWIDTH) ? REPORTWIDTH : num;
+        swrite(spaces, sizeof(char), bytes, out);
+        num -= bytes;
+    }
+}
 
 static void centre(stream *out, const char *s, bool breaking)
 {
@@ -140,9 +147,8 @@ static void centre(stream *out, const char *s, bool breaking)
         freestrlist(T);
     }
     else {
-        swrite(spaces, sizeof(char), (REPORTWIDTH - strlen(s) + 1) / 2, out);
+        write_spaces(out, (REPORTWIDTH - strlen(s) + 1) / 2);
         sputs(s, out);
-        newline(out);
     }
 }
 
@@ -176,16 +182,16 @@ char marker)
         const char *last_space = begin;
 
         if (mark && indent >= 2) {
-            swrite(spaces, sizeof(char), indent - 2, out);
+            write_spaces(out, indent - 2);
             swrite(mark, sizeof(char), 1, out);
-            swrite(spaces, sizeof(char), 1, out);
+            write_spaces(out, 1);
             mark = 0;
         }
         else if (begin == str) {
-            swrite(spaces, sizeof(char), indent, out);
+            write_spaces(out, indent);
         }
         else {
-            swrite(spaces, sizeof(char), indent + hanging_indent, out);
+            write_spaces(out, indent + hanging_indent);
         }
         while (*end && end <= begin + length - indent) {
             if (*end == ' ') {

src/report.h

@@ -15,8 +15,10 @@
 extern "C" {
 #endif
 
+    struct stream;
     void register_nr(void);
     void report_cleanup(void);
+    void write_spaces(struct stream *out, size_t num);
 
 #ifdef __cplusplus
 }

src/reports.test.c

@@ -1,6 +1,7 @@
 #include <platform.h>
 #include <config.h>
 #include "reports.h"
+#include "report.h"
 
 #include <kernel/building.h>
 #include <kernel/faction.h>
@@ -10,6 +11,8 @@
 #include <kernel/unit.h>
 
 #include <quicklist.h>
+#include <stream.h>
+#include <memstream.h>
 
 #include <CuTest.h>
 #include <tests.h>
@@ -98,11 +101,43 @@ static void test_seen_faction(CuTest *tc) {
     CuAssertTrue(tc, f1->no < f2->no);
 }
 
+static void test_write_spaces(CuTest *tc) {
+    stream out = { 0 };
+    char buf[1024];
+    size_t len;
+
+    mstream_init(&out);
+    write_spaces(&out, 4);
+    out.api->rewind(out.handle);
+    len = out.api->read(out.handle, buf, sizeof(buf));
+    buf[len] = '\0';
+    CuAssertStrEquals(tc, "    ", buf);
+    CuAssertIntEquals(tc, ' ', buf[3]);
+    mstream_done(&out);
+}
+
+static void test_write_many_spaces(CuTest *tc) {
+    stream out = { 0 };
+    char buf[1024];
+    size_t len;
+
+    mstream_init(&out);
+    write_spaces(&out, 100);
+    out.api->rewind(out.handle);
+    len = out.api->read(out.handle, buf, sizeof(buf));
+    buf[len] = '\0';
+    CuAssertIntEquals(tc, 100, (int)len);
+    CuAssertIntEquals(tc, ' ', buf[99]);
+    mstream_done(&out);
+}
+
 CuSuite *get_reports_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
     SUITE_ADD_TEST(suite, test_reorder_units);
     SUITE_ADD_TEST(suite, test_seen_faction);
     SUITE_ADD_TEST(suite, test_regionid);
+    SUITE_ADD_TEST(suite, test_write_spaces);
+    SUITE_ADD_TEST(suite, test_write_many_spaces);
     return suite;
 }