Fixes #121: Now properly accounting for a 2-character prefix for %#b, like for %#x, when a precision is field width is specified and we are matching it exactly. Also, added some test suite checks for this bug.

Author: eyalroz

src/printf/printf.c

@@ -485,10 +485,10 @@ static void print_integer_finalization(output_gadget_t* output, char* buf, print
       // Let's take back some padding digits to fit in what will eventually
       // be the format-specific prefix
       if (unpadded_len < len) {
-        len--;
+        len--; // This should suffice for BASE_OCTAL
       }
-      if (len && (base == BASE_HEX) && (unpadded_len < len)) {
-        len--;
+      if (len && (base == BASE_HEX || base == BASE_BINARY) && (unpadded_len < len)) {
+        len--; // ... and an extra one for 0x or 0b
       }
     }
     if ((base == BASE_HEX) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_INTEGER_BUFFER_SIZE)) {

test/test_suite_main_testcases.hpp

@@ -190,7 +190,11 @@ PRINTF_TEST_CASE(sharp_flag)
 PRINTF_TEST_CASE(sharp_flag__non_standard_format)
 {
   char buffer[base_buffer_size];
-  PRINTING_CHECK("0b110",                ==, sprintf_, buffer, "%#b", 6);
+  PRINTING_CHECK("0b110",                ==, sprintf_, buffer, "%#b",    6);
+  PRINTING_CHECK("0b11111111",           ==, sprintf_, buffer, "%#010b", 0xff);
+  PRINTING_CHECK("0b011111111",          ==, sprintf_, buffer, "%#011b", 0xff);
+  PRINTING_CHECK("077",                  ==, sprintf_, buffer, "%#03o",  077);
+  PRINTING_CHECK("0077",                 ==, sprintf_, buffer, "%#04o",  077);
 }
 
 #endif